Method, device and medium for generating chemical reaction paths based on quantum computing

Abstract

The present invention discloses a method, device and medium for generating a chemical reaction path based on quantum computing, the method comprising: obtaining an expected reaction path based on a target chemical reaction, wherein the expected reaction path includes a number of target molecules; preparing a test state corresponding to each of the target molecules, and measuring the average energy of each of the test states; when all the average energies meet a preset condition, generating a final reaction path of the target chemical reaction, wherein the preset condition is a preset accuracy of the difference between the current average energy and the previous average energy measured for the same test state. The embodiments of the present invention can improve the calculation speed while accurately generating chemical reaction paths, and promote the further development of quantum chemical simulation applications.

Description

Technical Field

[0001] The present invention belongs to the field of quantum computing technology, and in particular to a method, device and medium for generating a chemical reaction path based on quantum computing. Background Art

[0002] Quantum computers are physical devices that follow the laws of quantum mechanics to perform high-speed mathematical and logical operations, store and process quantum information. When a device processes and calculates quantum information and runs quantum algorithms, it is a quantum computer. Quantum computers have become a key technology under research because they have the ability to process mathematical problems more efficiently than ordinary computers. For example, they can speed up the time to crack RSA keys from hundreds of years to a few hours.

[0003] Quantum computing simulation is a simulation that uses numerical calculations and computer science to simulate the laws of quantum mechanics. As a simulation program, it uses the basic laws of quantum bits in quantum mechanics and the high-speed computing power of computers to describe the spatiotemporal evolution of quantum states. Quantum chemistry uses the characteristics of quantum computing simulation to study chemical problems.

[0004] With the continuous improvement of quantum chemical theory, computational chemistry has become an important tool for chemists to explain experimental phenomena, predict experimental results, and guide experimental design. It has been widely used in the synthesis of drugs, the preparation of catalysts, etc., and a prerequisite for these applications is to obtain accurate chemical reaction paths. Otherwise, it is very likely to provide chemists with wrong guidance, thus hindering the development of quantum chemical simulation applications. To obtain accurate reaction paths, huge orders of magnitude of calculations are required, and these calculations will increase exponentially with the increase in the size of molecules in chemical reactions. However, in the face of such a large amount of calculations, classical computers appear to have limited capabilities in terms of calculation accuracy and calculation size, which to a certain extent limits the development of computational chemistry, resulting in weak applications of users to simulate chemical systems, affecting the further development of quantum chemical simulation applications. Summary of the invention

[0005] The purpose of the present invention is to provide a method, device and medium for generating chemical reaction paths based on quantum computing to address the deficiencies in the prior art. It can accurately generate chemical reaction paths while improving the calculation speed and promoting the further development of quantum chemical simulation applications.

[0006] An embodiment of the present application provides a method for generating a chemical reaction path based on quantum computing, the method comprising:

[0007] Based on the target chemical reaction, obtaining an expected reaction path, wherein the expected reaction path includes a number of target molecules;

[0008] preparing a test state corresponding to each of the target molecules respectively, and measuring the average energy of each of the test states;

[0009] When all the average energies meet the preset conditions, a final reaction path of the target chemical reaction is generated, wherein the preset conditions are the preset accuracy of the difference between the current average energy and the previous average energy measured for the same test state, and the final reaction path contains the target molecules corresponding to the test state whose average energy meets the preset conditions.

[0010] Optionally, the method further includes:

[0011] When there is an average energy among all the average energies that does not satisfy the preset condition, prepare a test state corresponding to the molecule to be measured, and return to the step of measuring the average energy of each test state until the average energy of the test state of the molecule to be measured meets the preset condition, wherein the molecule to be measured is a target molecule whose average energy of the test state does not satisfy the preset condition.

[0012] Optionally, obtaining an expected reaction path based on a target chemical reaction includes:

[0013] Obtaining a target transition state of the target chemical reaction;

[0014] The expected reaction pathway is determined based on the target transition state.

[0015] Optionally, obtaining a target transition state of the target chemical reaction includes:

[0016] Obtaining a functional form and basis set for the target chemical reaction;

[0017] Based on the initial guess of the transition state structure of the target chemical reaction, the target transition state is obtained using the functional form and the basis set.

[0018] Optionally, determining the expected reaction path according to the target transition state includes:

[0019] The expected reaction pathway is determined based on the target transition state, the functional form and the basis set.

[0020] Optionally, the plurality of target molecules include reactants, products and the target transition state in the target chemical reaction.

[0021] Optionally, the step of separately preparing a test state corresponding to each target molecule comprises:

[0022] Respectively obtaining the orbital and electron number of each of the target molecules;

[0023] Determining a cluster operator of the fermion form of each of the target molecules based on the orbital and the number of electrons of the target molecule;

[0024] For each of the target molecules, based on the cluster operator in the fermion form of the target molecule, the test state corresponding to the target molecule is obtained.

[0025] Optionally, determining the cluster operator of the fermion form of each target molecule based on the orbital and the number of electrons of the target molecule comprises:

[0026] Obtaining the Hartree-Fock state of each target molecule according to the target orbital and the number of electrons of each target molecule;

[0027] For each of the target molecules, the cluster operator and the number of excitation terms of the fermion form of the target molecule are determined according to a pre-selected assumption method and the Hartree-Fock state of the target molecule.

[0028] Optionally, measuring the average energy of each test state includes:

[0029] Obtaining the fermion Hamiltonian corresponding to each of the target molecules respectively;

[0030] For each target molecule, transform the fermion Hamiltonian corresponding to the target molecule into the Pauli Hamiltonian of the target molecule;

[0031] For each of the target molecules, quantum circuits corresponding to the sub-items are constructed according to the sub-items, and the average energy of the test state of the target molecule is measured using the quantum circuits, wherein the sub-items are obtained by decomposing the Pauli Hamiltonian of the target molecule.

[0032] Another embodiment of the present application provides a device for generating a chemical reaction path based on quantum computing, the device comprising:

[0033] An acquisition module, used to obtain an expected reaction path based on a target chemical reaction, wherein the expected reaction path includes a number of target molecules;

[0034] A measurement module, used to prepare a test state corresponding to each target molecule and measure the average energy of each test state;

[0035] A generation module is used to generate a final reaction path of the target chemical reaction when all the average energies meet a preset condition, wherein the preset condition is a preset accuracy of the difference between the current average energy and the previous average energy measured for the same test state, and the final reaction path contains the target molecule corresponding to the test state whose average energy meets the preset condition.

[0036] Optionally, the device further comprises:

[0037] A preparation module is used to prepare a test state corresponding to the molecule to be measured when there is an average energy that does not meet the preset condition among all the average energies, and return to the step of measuring the average energy of each of the test states until the average energy of the test state of the molecule to be measured meets the preset condition, wherein the molecule to be measured is a target molecule whose average energy in the test state does not meet the preset condition.

[0038] Optionally, the obtaining module includes:

[0039] An obtaining unit, used to obtain a target transition state of the target chemical reaction;

[0040] The first determining unit is used to determine the expected reaction path according to the target transition state.

[0041] Optionally, the obtaining unit includes:

[0042] A first acquisition subunit is used to obtain a functional form and a basis set for the target chemical reaction;

[0043] The second acquisition subunit is used to obtain the target transition state based on the initial guess of the transition state structure of the target chemical reaction using the functional form and the basis set.

[0044] Optionally, the first determination unit is specifically used to determine the expected reaction path according to the target transition state, the functional form and the basis set.

[0045] Optionally, the plurality of target molecules include reactants, products and the target transition state in the target chemical reaction.

[0046] Optionally, the measurement module includes:

[0047] A first acquisition unit, used to respectively acquire the orbital and the number of electrons of each of the target molecules, wherein the orbital includes the target orbital;

[0048] A second determination unit is used to determine the cluster operator of the fermion form of each target molecule based on the target orbital and the number of electrons of each target molecule;

[0049] The second acquisition unit is used to acquire, for each target molecule, a test state corresponding to the target molecule based on the cluster operator in the fermion form of the target molecule.

[0050] Optionally, the second determining unit includes:

[0051] An acquisition subunit, used for acquiring the Hartree-Fock state of each target molecule according to the target orbital and the number of electrons of each target molecule;

[0052] The determination subunit is used to determine the cluster operator and the number of excitation items of the fermion form of each target molecule according to a pre-selected assumption method and the Hartree-Fock state of the target molecule.

[0053] Optionally, the measurement module further includes:

[0054] A third acquisition unit is used to respectively acquire the fermion Hamiltonian corresponding to each of the target molecules;

[0055] A transformation unit, for transforming, for each target molecule, the fermion Hamiltonian corresponding to the target molecule into the Pauli Hamiltonian of the target molecule;

[0056] The measuring unit is used for constructing quantum circuits corresponding to each of the sub-items for each of the target molecules according to the sub-items, and measuring the average energy of the test state of the target molecule using the quantum circuit, wherein the sub-items are obtained by decomposing the Pauli Hamiltonian of the target molecule.

[0057] An embodiment of the present application provides a storage medium, in which a computer program is stored, wherein the computer program is configured to execute any of the above methods when running.

[0058] An embodiment of the present application provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to execute any one of the methods described above.

[0059] Compared with the prior art, the present invention first obtains the expected reaction path based on the target chemical reaction; then prepares the test state corresponding to each target molecule and measures the average energy of each test state; then, when all the average energies meet the preset conditions, the final reaction path of the target chemical reaction is generated. In this way, quantum computing can accurately generate reaction paths and improve computing speed, promoting the further development of quantum chemical simulation applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 A hardware structure block diagram of a computer terminal for a method for generating a chemical reaction path based on quantum computing provided by an embodiment of the present invention;

[0061] Figure 2 A schematic flow chart of a method for generating a chemical reaction path based on quantum computing provided in an embodiment of the present invention;

[0062] Figure 3 A schematic diagram of the structure of a target transition state provided by an embodiment of the present invention;

[0063] Figure 4 A schematic diagram of an expected chemical reaction pathway provided by an embodiment of the present invention;

[0064] Figure 5 A schematic diagram of orbital information of a molecule provided by an embodiment of the present invention;

[0065] Figure 6 A schematic diagram of a quantum circuit structure corresponding to a proposed method provided in an embodiment of the present invention;

[0066] Figure 7 A schematic diagram of a quantum circuit constructed according to a Pauli operator form cluster operator provided in an embodiment of the present invention;

[0067] Figure 8 Schematic diagram of a quantum circuit corresponding to each sub-item of the Pauli Hamiltonian of a hydrogen molecule provided by an embodiment of the present invention

[0068] Fig. 9 A schematic diagram of a chemical synthesis pathway generated by the method provided in an embodiment of the present invention and a classical method;

[0069] Fig.10 A schematic diagram of the structure of a device for generating a chemical reaction path based on quantum computing provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0070] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, but should not be construed as limiting the present invention.

[0071] The embodiment of the present invention first provides a method for generating a chemical reaction path based on quantum computing. The method can be applied to electronic devices, such as computer terminals, specifically ordinary computers, quantum computers, etc.

[0072] The following describes it in detail by taking running on a computer terminal as an example. Figure 1 The hardware structure block diagram of a computer terminal for a method for generating a chemical reaction path based on quantum computing provided by an embodiment of the present invention. Figure 1 As shown, the computer terminal may include one or more ( Figure 1Only one is shown in the figure) a processor 102 (the processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA) and a memory 104 for storing data. Optionally, the computer terminal may also include a transmission device 106 for communication functions and an input and output device 108. It can be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the above-mentioned computer terminal. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations are shown.

[0073] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / modules corresponding to the method for generating a chemical reaction path based on quantum computing in the embodiment of the present application. The processor 102 executes various functional applications and data processing by running the software programs and modules stored in the memory 104, that is, implementing the above method. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories may be connected to a computer terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0074] The transmission device 106 is used to receive or send data via a network. The specific example of the above network may include a wireless network provided by a communication provider of a computer terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0075] Quantum computing is a new computing model that follows the laws of quantum mechanics to control quantum information units for computing. The most basic principle of quantum computing is the principle of quantum mechanical superposition. The principle of quantum mechanical superposition allows the state of quantum information units to be in a superposition state of multiple possibilities, making quantum information processing more efficient than classical information processing. A quantum system contains several particles that move according to the laws of quantum mechanics. This system is said to be in a certain quantum state in the state space. For chemical molecules, quantum chemical simulation can be realized to provide research support for quantum computing.

[0076] It should be noted that a true quantum computer is a hybrid structure, which consists of two parts: one part is a classical computer, which is responsible for performing classical calculations and control; the other part is a quantum device, which is responsible for running quantum programs and thus realizing quantum computing. A quantum program is a sequence of instructions written in a quantum language such as QRunes that can be run on a quantum computer, which supports quantum logic gate operations and ultimately realizes quantum computing. Specifically, a quantum program is a sequence of instructions that operate quantum logic gates in a certain sequence.

[0077] In practical applications, due to the limitations of the development of quantum device hardware, quantum computing simulation is usually required to verify quantum algorithms, quantum applications, etc. Quantum computing simulation is the process of simulating the operation of quantum programs corresponding to specific problems using a virtual architecture (i.e., quantum virtual machine) built with the resources of ordinary computers. Usually, it is necessary to build a quantum program corresponding to a specific problem. The quantum program referred to in the embodiment of the present invention is a program written in a classical language to characterize quantum bits and their evolution, in which quantum bits, quantum logic gates, etc. related to quantum computing are represented by corresponding classical codes.

[0078] Quantum circuits, as a manifestation of quantum programs, are also called quantum logic circuits. They are the most commonly used general quantum computing model. They represent circuits that operate on quantum bits in an abstract concept. They are composed of quantum bits, circuits (timelines), and various quantum logic gates. Finally, the results often need to be read out through quantum measurement operations.

[0079] Unlike traditional circuits that are connected by metal wires to transmit voltage or current signals, in quantum circuits, the circuits can be seen as connected by time, that is, the state of the quantum bit evolves naturally over time, following the instructions of the Hamiltonian operator until it encounters a logic gate and is operated.

[0080] A quantum program as a whole corresponds to a total quantum circuit. The quantum program described in the present invention refers to the total quantum circuit, wherein the total number of quantum bits in the total quantum circuit is the same as the total number of quantum bits in the quantum program. It can be understood that a quantum program can be composed of a quantum circuit, measurement operations on quantum bits in the quantum circuit, registers for storing measurement results, and control flow nodes (jump instructions). A quantum circuit can contain dozens, hundreds, or even thousands of quantum logic gate operations. The execution process of a quantum program is the process of executing all quantum logic gates in a certain time sequence. It should be noted that the time sequence is the time order in which a single quantum logic gate is executed.

[0081] It should be noted that in classical computing, the most basic unit is the bit, and the most basic control mode is the logic gate, which can achieve the purpose of controlling the circuit through the combination of logic gates. Similarly, the way to process quantum bits is quantum logic gates. Using quantum logic gates, quantum states can evolve. Quantum logic gates are the basis of quantum circuits. Quantum logic gates include single-bit quantum logic gates, such as Hadamard gates (H gates, Hadamard gates), Pauli-X gates (X gates), Pauli-Y gates (Y gates), Pauli-Z gates (Z gates), RX gates, RY gates, RZ gates, etc.; two-bit or multi-bit quantum logic gates, such as CNOT gates, CR gates, CZ gates, iSWAP gates, Toffoli gates, etc. Quantum logic gates are generally represented by unitary matrices, which are not only matrix forms, but also operations and transformations. The effect of general quantum logic gates on quantum states is calculated by multiplying the unitary matrix on the left by the matrix corresponding to the right vector of the quantum state.

[0082] The quantum state, that is, the logical state of the quantum bit, is represented by binary in the quantum algorithm (or quantum program). For example, a group of quantum bits is q0, q1, and q2, representing the 0th, 1st, and 2nd quantum bits, and is sorted from high to low as q2q1q0. The quantum state corresponding to this group of quantum bits is the superposition of the eigenstates corresponding to this group of quantum bits. The eigenstates corresponding to this group of quantum bits have 2 to the power of the total number of quantum bits, that is, 8 eigenstates (determined states): |000>, |001>, |010>, |011>, |100>, |101>, |110>, |111>, and the bit of each eigenstate corresponds to the quantum bit. For example, in the |000> state, 000 corresponds to q2q1q0 from high to low, and |> is the Dirac symbol.

[0083] Using a single qubit to illustrate, the logical state of a single qubit It may be in the |0> state, |1> state, or the superposition state of |0> state and |1> state (uncertain state), which can be specifically expressed as Where c and d are complex numbers representing the amplitude (probability amplitude) of the quantum state, and the square of the amplitude modulus |c| 2 and |d| 2 denote the probabilities of the |0> and |1> states, respectively, and |c| 2 +|d| 2 = 1. In short, the quantum state is a superposition state composed of various eigenstates. When the probability of other eigenstates is 0, it is in the only determined eigenstate.

[0084] For a long time, the theoretical explanation of the energy and properties of molecules and materials at the atomic level has been considered one of the most direct applications of quantum computing, and it has received widespread attention as a new computing paradigm. Compared with classical computing, the computing power of quantum computing increases exponentially with the increase in the number of quantum bits. With continuous development, breakthroughs have occurred in many fields, including pharmaceuticals, photovoltaics, aviation, electronics, and energy generation. One of the most likely applications of quantum computers is to simulate quantum systems, among which molecules are common quantum systems in nature. Finding the initial experimental state of a molecular system is an important prerequisite and step for calculating the energy of a molecular system, and is also one of the main goals of quantum chemistry.

[0085] See also Figure 2 , Figure 2 A schematic flow chart of a method for generating a chemical reaction path based on quantum computing provided in an embodiment of the present invention may include the following steps:

[0086] S201: Based on a target chemical reaction, an expected reaction pathway is obtained, wherein the expected reaction pathway includes a number of target molecules.

[0087] Exemplarily, the target chemical reaction can be an SN2 (bicolecular nucleophilic substitution) reaction of chloride ions attacking chloromethane, or a diazene molecular isomerization reaction, or a copper-catalyzed intramolecular coupling reaction of 2-(2-iodophenyl)-1-ethanol. Of course, these are just examples, and the target chemical reactions are not limited to these, so they will not be described one by one.

[0088] The reaction pathway includes molecules in the process of changing from reactants to products, showing the process of molecular structure change.

[0089] In an embodiment of the present invention, a series of reaction paths can be obtained based on the structure and reaction type of the reactants in the target chemical reaction, and one of these reaction paths can be selected as an expected reaction path. The selection can be random, or the reaction path can be finally determined based on various parameters as the expected reaction path.

[0090] Specifically, based on the target chemical reaction, obtaining the expected reaction path may include:

[0091] Obtaining a target transition state of the target chemical reaction;

[0092] The expected reaction pathway is determined based on the target transition state.

[0093] The transition state, specifically the transition state structure, is the highest energy point on the reaction path on the potential energy surface. It is a structure that connects reactants and products through the minimum energy path (MEP) (if it is a multi-step reaction mechanism, the reactants or products here include intermediates). For reactions between multiple molecules, more precisely, the transition state structure connects the complex structure formed by van der Waals forces and electrostatic forces after they are infinitely close, and the complex structure when the reaction is completed but not yet infinitely far away.

[0094] To obtain the target transition state, a transition state search algorithm can be used. The transition state search algorithm includes algorithms based on initial guess structures, such as the Newton-Raphson method and the quasi-Newton method; algorithms based on reactant structures and product structures, such as the simultaneous transformation method; algorithms based on reactant structures, such as the slowest ascent method, the equipotential surface search method, and the like.

[0095] In a chemical reaction, there are many transition states. The target transition state is one of all transition states. The target transition state is selected from all transition states. Different selection methods can be set according to actual needs to select the target transition state. After obtaining the target transition state, the expected reaction path can be determined according to the target transition state.

[0096] Specifically, obtaining a target transition state of a target chemical reaction may include:

[0097] Obtaining a functional form and basis set for the target chemical reaction;

[0098] Based on the initial guess of the transition state structure of the target chemical reaction, the target transition state is obtained using the functional form and the basis set.

[0099] Functional, in simple terms, is a function with the entire function as the independent variable. There are many functional forms, and you can choose the functional form according to your actual needs. For example, you can choose B3LYP functional, which is a functional in DFT (Density Functional Theory). Functional forms can also be M06-2X, wB97XD or CAM-B3LYP, etc.

[0100] The basis set is actually a set of templated functions. The most critical part of quantum chemical calculations is to solve the wave functions of each energy level of the molecule. According to the idea of ​​molecular orbital theory, molecular orbitals can be fitted by linear combinations of atomic orbitals. Therefore, we can take a set of atomic wave functions (basis functions) as the basis and mix them to solve the wave functions. All the basis functions used to describe an atom are called a basis set. In an embodiment of the present invention, the basis set can be 6-31+G*, specifically 6-31+G(d), or it can be 3-21G, 6-21G, 4-31G, 6-311G, def2-TZVP, def2-QZVP, cc-pVTZ, etc.

[0101] The initial guess of the transition state structure can be obtained and input by the technician based on experience; it can also be selected from the pre-stored transition state structures for the target chemical reaction; of course, it can also be obtained by calculation, for example, based on the reactants in the target chemical reaction and the redundant coordinates of the reactants, the redundant coordinates are scanned. The old bonds (bonds to be broken) or new bonds (bonds to be formed) are scanned using the redundant internal coordinate scanning method. After the scan is completed, the potential energy change curve when the old bond is broken and the new bond is formed is obtained. The molecular structure corresponding to the highest energy point on the potential energy change curve is used as the initial guess of the transition state structure.

[0102] After obtaining the initial guess of the transition state structure, functional form and basis set, the Berny algorithm can be used to search for the target transition state. When a transition state is found, the vibration frequency of the transition state is calculated. If the vibration frequency is an imaginary frequency and the vibration direction of the imaginary frequency is consistent with the reaction direction, then the transition state is the target transition state. Otherwise, the target transition state needs to be found.

[0103] For example, taking the SN2 reaction of methyl chloride (CH3Cl) and chloride ion (Cl-) as an example, using the B3YLP functional and the 6-31+G* basis set, using Berny to search for transition states, and calculating the vibration frequency of the found transition state, an imaginary frequency (-328.48cm-1) is obtained, and the vibration direction of the imaginary frequency is consistent with the direction of the SN2 reaction. Then the transition state is the target transition state, and the target transition state structure is as follows: Figure 3 shown.

[0104] Specifically, determining the expected reaction path according to the target transition state includes:

[0105] The expected reaction pathway is determined based on the target transition state, the functional form and the basis set.

[0106] The target transition state and expected reaction path use the same functional form and basis set, ensuring that the calculation is at the same calculation level, thereby obtaining a more accurate expected reaction path.

[0107] Specifically, the expected reaction path can be obtained by using the IRC (intrinsic reaction coordinate) method according to the target transition state, functional form and basis set. MEP (minimum energy path) refers to the path with the lowest energy from one point to another on the potential energy surface that satisfies the principle of least action. If the MEP under the mass weight coordinate connects the reactants, transition structure and products, it is called IRC. The so-called mass weight coordinate in Cartesian coordinates is r(i,x) = sqrt(m(i))*R(i,x), where m(i) is the mass of atom i, R(i,x) is the original x-direction coordinate of atom i, and there are also r(i,y) and r(i,z). IRC describes the path (steepest descent path) from the transition state along the negative gradient direction of potential energy under mass weight coordinates when the speed of atomic nuclei is infinitely small, where the negative gradient direction of each point is the direction of movement of the nucleus here, and the energy minimum point is perpendicular to the path direction. Specifically, the LQA (Local quadratic approximation) algorithm can be used to calculate the expected reaction path. LQA is a very traditional IRC generation algorithm proposed in 1988. Each step requires the use of the Hessian matrix. By default, it is generated by the Bofill method based on the gradient and the Hessian approximation of the previous step. It should be noted that the expected reaction path is a smooth reaction path. Continuing with the above example, the expected reaction path of the SN2 reaction is as follows Figure 4 shown.

[0108] In an embodiment of the present invention, a portion of molecules are selected as target molecules from the expected reaction path. The selection can be random or according to certain rules. For example, a molecule is selected as the starting point, and a molecule is selected every 2 molecules until the end of the reaction path. Specifically, the plurality of target molecules include reactants, products and target transition states in the target chemical reaction. The expected reaction path obtained in this way can more accurately reflect the reaction process.

[0109] S202: preparing a test state corresponding to each target molecule respectively, and measuring the average energy of each test state.

[0110] In an embodiment of the present invention, a quantum circuit is constructed based on a target molecule, and a simulated evolution is performed according to the constructed quantum simulation circuit, and the quantum state obtained after the evolution is the experimental state of the target molecule.

[0111] In one embodiment of the present invention, preparing the test state corresponding to each target molecule separately may include:

[0112] Step A: respectively obtaining the target orbital and the number of electrons of each target molecule.

[0113] Because the expected reaction path includes several target molecules, here, for each target molecule, it is necessary to obtain the target orbital and the number of electrons of the target molecule.

[0114] Orbital is a mathematical method that describes the probability of finding an electron in a specific space outside the nucleus of a molecule, and points out the possible position of the electron in three-dimensional space; the number of electrons is the number of electrons contained in the target molecule. Electrons are a type of elementary particle and generally refer to the number of electrons outside the nucleus of a molecule.

[0115] Molecular orbitals can be formed by linear combinations of corresponding atomic orbitals. When several atomic orbitals are combined, several molecular orbitals are formed. The energy levels of electrons in a molecule are called molecular orbitals, which are formed by the interaction of the atomic orbitals that make up the molecule. A molecular orbital can accommodate up to two electrons with opposite spin directions. The electrons in an orbit have a certain energy, and the range of motion of the electrons in the orbit (i.e., the shape of the orbit) can be represented by a certain outline, which can be described by a wave function.

[0116] It should be noted that the target orbital is a non-frozen orbital. Among them, the frozen orbital is: the innermost orbital of the target system or any orbital except the outermost orbital. Freezing some orbits is to localize certain electrons, prevent electron transfer, and facilitate subsequent calculations. The innermost electron orbital of the molecule is closest to the nucleus and has the lowest energy. Starting from the innermost orbit and moving outward, the energy of the electron orbit increases successively. The outermost electron orbital is farthest from the nucleus and has the highest energy. At this time, the electron is about to break free from the constraints of the nucleus.

[0117] For example, Figure 5 The orbital information diagram of the molecule was simulated, where area A represents the unfrozen orbital and area D represents the frozen orbital. By expanding the electron orbital function to a finite basis function, they greatly reduced the difficulty of solving the molecular Hartree-Fock problem. The wave function of the molecule in the figure can be written as:

[0118]

[0119] Among them, the wave function of the non-frozen orbit Φ A and the wave function Φ of the frozen orbit D Satisfy Φ respectively A =Φ A (1, 2, ..., N A ), ΦD =Φ D (N A +1,N A +2,…,N A +N D ), is the Slater type antisymmetric coefficient, N A 、N D Represents electron orbitals.

[0120] The multi-electron wave function can be written as:

[0121]

[0122] Among them, ψ1 is the innermost orbital close to the nucleus, Θ V is the valence electron wave function, V represents the valence electron orbit, α, β, μ represent the electron orbit. Therefore, the multi-electron energy corresponding to the above wave function is:

[0123]

[0124] The above formula can be simplified to the sum of nuclear energy and valence energy

[0125] Among them, E core represents the energy of the nucleus, H V is the Hamiltonian of valence electrons, satisfying h′(v)=h+∑ c (2J c -K c ), where h, ∑ c (2J c -K c ) correspond to the single-electron operator and the double-electron operator of valence electrons respectively, and v and v′ represent valence electron orbitals.

[0126] Note that the single-electron operator now has a Coulomb (J c ) and exchange (K c ) potential. The core energy has the standard form of a closed shell determinant wave function, namely:

[0127]

[0128] Among them, c and c′ represent the electrons in the nucleus. This simplified method is used to solve the valence electron wave function Θ V , called the frozen orbit approximation. This is a necessary approximation in all practical ab initio reductions to valence electrons only, and the quality of all such reductions is therefore limited by the frozen orbit approximation. V, one must explicitly make valence space orthogonal to core space. This means that one must evaluate all two-electron integrals from the full-electron basis set and then transform them into a reduced valence basis set that is orthogonal to core space. Thus, the frozen orbital approximation saves considerable computational effort.

[0129] Step B: Based on the target orbital and the number of electrons of each of the target molecules, determine the cluster operator of the fermion form of the target molecule.

[0130] For a target molecule, after obtaining the target orbital and the number of electrons of the target molecule, the cluster operator of the fermion form of the target molecule can be determined. Specifically, the cluster operator can be understood as a type of artificially defined operator used to represent the jumping of electrons on the orbital.

[0131] Specifically, to determine the cluster operator of the fermion form of each target molecule, it is first necessary to obtain the Hartree-Fock state of the target molecule according to the target orbital and the number of electrons of the target molecule.

[0132] For example, lithium hydride contains 12 single-electron spin molecular orbitals and 4 electrons. According to the number of lithium hydride electrons and orbital information, if a quantum bit represents a spin molecular orbital, that is, 0 represents an empty orbital and 1 represents an occupied orbital, the Hartree-Fock state of the lithium hydride target system can be represented by the quantum state |000000001111>. Therefore, for any N-electron system containing M spin molecular orbitals, its Hartree-Fock can be simply represented in this way. As long as M quantum bits are given in the quantum circuit, and then a NOT gate is added to the first N quantum circuits, the required Hartree-Fock state of the N-electron system can be obtained.

[0133] It should be noted that in quantum computing, the selection of wave functions requires a reference wave function as a basis vector. For example, in quantum chemistry, the Hartree-Fock state vector is generally used as a reference wave function to satisfy:

[0134] ψ(θ)=U(θ)|ψ> Hartree-Fock

[0135] Where ψ(θ) represents the wave function corresponding to a set of parameters θ, U(θ) represents the matrix operator corresponding to a set of parameters θ, and the reference wave function |ψ> Hartree-Fock Corresponding to the Hartree-Fock ground state in chemistry, it means that the electrons of the molecule are all in the lowest orbital.

[0136] Secondly, according to the pre-selected assumption method and the Hartree-Fock state of the target molecule, the cluster operator and the number of excitation terms in the fermion form of the target system are determined.

[0137] Suppose that a prepared molecule is in its initial state, for example |ψ> Hartree-Fock The method of evolving to quantum circuits can be pre-selected as the coupled cluster method (CC), which is a method that starts from the Hartree-Fock molecular orbital and obtains the experimental state |ψ> through assumptions. The assumption here is the exponential coupled cluster operator e T , satisfying: |ψ>=e T |ψ> Hartree-Fock , the T in the assumption is that it is the N electron cluster operator, and its definition is the sum of several excitation operators, that is:

[0138] T=T1+T2+…+T N

[0139] Among them, T1 is the single-particle excitation operator, T2 is the double-particle excitation operator, and the rest are similar. Since the probability of triple excitation and quadruple excitation in a multi-electron system is very small, it is usually "cut off" at the double excitation point, and only T1 and T2 are left, that is:

[0140] T=T1+T2

[0141] in, To create the operator, a r 、a s is the annihilation operator, p, q, r, s represent orbits, and the unknown coefficient t pq ,t pqrs It is the parameter that needs to be found by the optimizer satisfy

[0142] It should be noted that after the initial state of the target molecule is converted into a cluster operator in the form of fermions by means of the pseudo-method, due to e T The exponentially coupled cluster operator is not a unitary operator, so it is not possible to directly convert e T The exponentially coupled cluster operator is mapped to quantum bits through a preset mapping method, and the corresponding quantum circuit cannot be constructed. Therefore, it is necessary to construct a unitary operator version of the exponentially coupled cluster operator, namely the unitary coupled cluster operator (UCC).

[0143] For example, we can first define an equivalent Hermitian Hamiltonian make Then, Generate UCC operators for generators: Among them, the simulation method includes single excitation coupling cluster or single-double excitation coupling cluster; when the simulation method is single excitation coupling cluster, the fermion form cluster operator of the target system includes the number of single excitation terms; when the simulation method is single-double excitation coupling cluster, the fermion form cluster operator of the target system includes the number of single excitation terms and the number of double excitation terms. That is, for the cluster operator T in UCC contains only T1, this simulation is called a single excitation coupling cluster (UCCS); if the cluster operator T in UCC contains T1 and T2, this simulation is called a single-double excitation coupling cluster (UCCSD).

[0144] Correspondingly, for UCCS and UCCSD, it is assumed that the corresponding quantum circuits are the same, for example Figure 6 As shown, Figure 6 Schematic diagram of quantum circuit structure corresponding to a proposed method, specifically a schematic diagram of a four-bit quantum circuit corresponding to the UCC method, and a schematic diagram of a quantum circuit of four quantum bits q0, q1, q2, and q3, where X -π / 2 , X π / 2 , Y -π / 2 , Y π / 2 Indicates the X gate and Y gate with parameters of -π / 2 and π / 2 respectively. Similarly, the icons Its solid line represents the CNOT gate, Z θ represents a Z gate with parameter θ. The pseudo principle displayed may include: a pseudo formula, for example, a matrix operator U(θ) corresponding to the quantum circuit. For UCC, the corresponding pseudo formula is:

[0145]

[0146] in, That is, P i For the generator.

[0147] Step C: for each target molecule, based on the cluster operator in the fermion form of the target molecule, obtaining the test state corresponding to the target molecule.

[0148] Specifically, for a target molecule, the steps to obtain the test state corresponding to the target molecule are as follows:

[0149] Step 1: Select a mapping method and transform the cluster operator in the form of fermion into the cluster operator in the form of Pauli operator.

[0150] The mapping method mentioned here is one of Jordan-Wigner transformation, Parity transformation, Bravyi-Kitaev transformation and SegmentParity transformation.

[0151] The mapping principle corresponding to each mapping method may include: state mapping principle and operator mapping principle. For example, for Jordan-Wigner transformation, the displayed state mapping is:

[0152]

[0153] in, represents the computational state of the quantum bit, represents the transformation matrix, represents the occupied state of the fermion system. The operator mapping shown is:

[0154]

[0155] in, represents the raising and lowering operator, j represents the quantum bit number, P represents the parity set, Z P(j) represents a set of Pauli Z matrices acting on quantum bits belonging to the parity set P, X represents the Pauli X matrix, and Y represents the Pauli Y matrix.

[0156] Equivalently, the operator mapping can also be shown as:

[0157]

[0158]

[0159] in, represents the generation operator, a j represents the annihilation operator, with a j They are collectively called the raising and lowering operators of the fermion system. represents the creation / annihilation operator on the quantum bit, represents the parity operator, and n represents the number of quantum bits.

[0160] The display methods of state mapping and operator mapping of other transformations are the same as the principles of Jordan-Wigner transformation, which will not be repeated here.

[0161] Step 2: Decompose the cluster operator in the form of Pauli operator into the corresponding unitary operator and evolve it, and obtain the evolved quantum state as the test state corresponding to the target molecule.

[0162] Specifically, following the above example, when the cluster operator in the form of fermions is transformed into the Pauli operator form through the Jordan-Wigner transformation, it is the sum of several sub-terms, and the expression is:

[0163]

[0164] Among them, σ is the Pauli operator, α, β∈(X, Y, Z, I), and i, j represent the subspace on which the cluster operator subterms act, and h is a real number.

[0165] However, if we sum these subterms, the resulting Pauli operator form cluster operator is difficult to diagonalize to generate a unitary operator. Therefore, in order to be able to use each subterm H k In order to decompose the UCC operator into a finite number of unitary operators for simulation, it is necessary to introduce the asymptotic approximation theorem, namely the Trotter Foluma, which is the core of the quantum simulation algorithm: lim n→∞ (e iAt / n e iBt / n )n=e i(A+B)t , where A and B are Hermitian operators, t is a real number, and n is a positive integer.

[0166] It should be noted that through the Toth formula, the exponential function can be decomposed into the approximate form of several sub-exponential function terms. The Toth decomposition emphasizes that the larger the n is, the closer it is to the original formula, rather than considering the specific value of n.

[0167] For example, for a molecule, the expression of the cluster operator T in the form of the Pauli operator after Jordan-Wigner transformation is as follows:

[0168]

[0169] The cluster operator in the form of the Pauli operator includes the same number of subterms as the number of excited terms.

[0170] According to the Tóth formula, based on the unitary operator corresponding to the cluster operator decomposition in the form of the Pauli operator, a quantum simulation circuit is constructed, that is, the H1 term is simulated first:

[0171]

[0172] Through deduction, it is concluded that the H1 term can be simulated by directly adding an RZ gate to the q0 quantum bit.

[0173] For the simulation of items H2, H3, H4, and H5, we can refer to item H1 and obtain:

[0174] U2(H2, θ2)=CNOT(0,1)RZ(1,2θ2)CNOT(0,1)

[0175] U3(H3, θ3)=CNOT(0,2)CNOT(1,2)RZ(2,2θ3)CNOT(1,2)CNOT(0,2)

[0176] U4(H4, θ4)=H(0)CNOT(0,1)RZ(1,2θ4)CNOT(0,1)H(0)

[0177]

[0178] Then, the quantum circuit for simulating the cluster operator T is constructed as Figure 7 As shown, the quantum simulation circuit is simulated and evolved, and the evolved quantum state is obtained as the test state corresponding to the molecule.

[0179] It should be emphasized that the proposed method can also be HE (Hardware Efficient) and SP (Symmetry Preserved) methods.

[0180] For the target molecule, when obtaining the test state corresponding to the target molecule, it is necessary to measure the average energy of the target molecule. The specific measurement steps are as follows:

[0181] Step 1: Obtain the fermion Hamiltonian corresponding to each target molecule.

[0182] Specifically, the Hamiltonian is the sum of the kinetic energy of all particles plus the potential energy of the particles associated with the system. For different situations or numbers of particles, the Hamiltonian is different because it includes the sum of the kinetic energy of the particles and the potential energy function corresponding to this situation, generally denoted by H. In quantum mechanics, the physical quantities of classical mechanics become corresponding operators, and the Hamiltonian corresponds to the Hamiltonian operator.

[0183] Specifically, based on the mechanical analysis of the target system, the Hamiltonian of this system can be obtained. To obtain the fermion Hamiltonian corresponding to the target system, the creation operator is required. and the annihilation operator a q To achieve this, they satisfy the anti-commutation relation.

[0184] For example, for a hydrogen molecule system, the corresponding fermion Hamiltonian is:

[0185] Step 2: For each target molecule, transform the fermion Hamiltonian corresponding to the target molecule into the Pauli Hamiltonian of the target molecule.

[0186] It should be noted that in quantum computing, the Hamiltonian in fermion form cannot be directly evolved on the circuit, so there needs to be a process to convert the expected value solution in integral form into a readable one for the quantum circuit, which is called mapping. It should be noted that mapping is just to express the Hamiltonian in another form, and the system energy information represented by each type of Hamiltonian is equivalent. In addition, for a quantum simulation circuit or a real quantum chip, the Pauli operator is easier to operate and generate, so the fermion Hamiltonian corresponding to the target system can be transformed into the Pauli Hamiltonian of the target system, which is convenient for subsequent simulation operations.

[0187] Continuing with the above example, for the hydrogen molecule system, the corresponding fermion Hamiltonian is transformed into the Pauli Hamiltonian, specifically:

[0188]

[0189] Step 3: For each of the target molecules, construct quantum circuits corresponding to the sub-items according to the sub-items, and use the quantum circuits to measure the average energy of the test state of the target molecule, wherein the sub-items are obtained by decomposing the Pauli Hamiltonian of the target molecule.

[0190] Specifically, obtain the experimental state |ψ of the target system to be solved n >, we need to start using the quantum expectation estimation algorithm to calculate the test state |ψ n >Energy on the molecular Hamiltonian. The so-called quantum expectation estimate means that the Hamiltonian H of the multi-electron system, Heisenberg model, quantum Ising model and other systems can be expanded into the sum of multiple sub-terms, that is:

[0191]

[0192] Among them, h is a real number, σ is the Pauli operator, α, β and γ∈(X, Y, Z, I), and i, j, k represent the subspace on which the Hamiltonian quantum term acts.

[0193] Since the observable is linear, when calculating the average energy of the system using the following formula:

[0194] E=<ψ * |H|ψ>

[0195] Among them, ψ * is orthogonal to ψ, and the right side of the equation can also be expanded into this form:

[0196]

[0197] It can be seen that we only need to calculate the expectation of each sub-item first, and then sum up the expectations to get the average energy E. It should be noted that the measurement of the expectation of each sub-item can be performed on a quantum processor, and the classical processor can be responsible for summing up the expectations.

[0198] For example, assuming that the Hamiltonian of a system is H, it can eventually be expanded into this form:

[0199]

[0200] In this formula, all sub-item coefficients h are 1, and it is assumed that the obtained test state is in the following form:

[0201] |ψ>=a|00>+b|01>+c|10>+d|11>

[0202] Among them, a 2 、b 2 、c 2 ,d 2 They refer to the probability P of collapsing to |00>, |01>, |10>, and |11> respectively when measuring the test state. S , applying each sub-term H1, H2, H3 of the Hamiltonian to the test state respectively, we can get the expected E1, E2, E3 in turn, specifically:

[0203] E1=<ψ * |H1|ψ>

[0204] E2=<ψ * |H2|ψ>

[0205] E3=<ψ * |H3|ψ>

[0206] Taking E1, E2, and E3 as examples, for the expected E1, the coefficient h is the expected value, and there is no need to construct line measurements, that is, For the expectation E2, its Hamiltonian is Since the measurement operation is performed at σ Z On (with σ Z The eigenvectors of are the subspace formed by the basis vectors), so we only need to add measurement gates to the quantum bits, and then pass the measurement results to the classical processor for summation.

[0207] Continuing with the above example, the Pauli Hamiltonian of the hydrogen molecule can be decomposed into 15 sub-terms, which respectively construct the entire hydrogen molecule Hamiltonian H p The measurement circuit of 15 sub-items is as follows Figure 8 The schematic diagram of the quantum circuit corresponding to each sub-item of the Pauli Hamiltonian of a hydrogen molecule is shown, and the expected E(i) of each sub-item can be obtained.

[0208] Specifically, by expanding the expected measurement circuits of each sub-item of the Pauli Hamiltonian of the target system, we can obtain the measurement circuits of each sub-item expectation E(i). The quantum processor then transmits E(i) to the classical processor in turn for summation, and the average energy of the molecule in the experimental state is obtained.

[0209] It should be noted that since the measurement operation is performed at σ Z For the x , σ y The Hamiltonian cannot be measured directly at this time, and it is necessary to measure σ x and σ y Perform a base change operation, that is, let the test state evolve again. x =H×σ Z ×H, That is, for σ x and σ y Before measurement, the Hadamard gate and The measurement results are then passed to a classical processor for summation.

[0210] S203: When all the average energies satisfy a preset condition, a final reaction path of the target chemical reaction is generated, wherein the preset condition is a preset accuracy of the difference between the current average energy and the previous average energy measured for the same test state, and the final reaction path includes the target molecule corresponding to the test state whose average energy satisfies the preset condition.

[0211] For a target molecule, after measuring the average energy of the target molecule, it is necessary to determine whether the current average energy meets the preset condition. The preset condition is that for the same target molecule, the difference between the current average energy and the previous measured average energy meets the preset accuracy. Specifically, for the same test state of the same target molecule, determine whether the difference between the current average energy and the previous measured average energy is within the preset accuracy range. If so, the test state corresponding to the average energy is exactly the ground state of the target molecule, and the energy E0 of the target molecule is directly obtained.

[0212] It should be noted that, when the average energy is measured for the first time, the average energy measured last time may be a predetermined value, such as 0, or other values.

[0213] When all target molecules meet the preset conditions, a final reaction path is generated, which includes the target molecules corresponding to the test state of the average energy that meets the preset conditions. Of course, the final reaction path can also include the average energy that meets the preset conditions. Exemplarily, the final reaction path can be a curve graph drawn with the average energy and its corresponding target molecule as the vertical and horizontal coordinates.

[0214] Specifically, the method may include:

[0215] When there is an average energy among all the average energies that does not meet the preset condition, the method may further include:

[0216] When there is an average energy among all the average energies that does not satisfy the preset condition, prepare a test state corresponding to the molecule to be measured, and return to the step of measuring the average energy of each test state until the average energy of the test state of the molecule to be measured meets the preset condition, wherein the molecule to be measured is a target molecule whose average energy in the test state does not satisfy the preset condition.

[0217] It should be noted that the average energy corresponding to some target molecules may meet the preset conditions, while some target molecules may not meet the preset conditions. The target molecules whose average energy does not meet the preset conditions need to be re-prepared in the test state and the corresponding average energy is measured. At this time, we call such target molecules molecules to be measured. For the molecules to be measured, gradient-independent algorithms such as the Nelder-Mead algorithm or gradient-dependent algorithms such as the gradient descent method can be used to optimize the parameters. Based on the optimized parameters Prepare new test states of the molecules to be measured, and continue to evolve and measure them, by continuously iterating the parameters To update the test state so that it can finally obtain the average energy that meets the preset conditions.

[0218] It can be seen that the present invention first obtains the expected reaction path based on the target chemical reaction; then prepares the test state corresponding to each target molecule and measures the average energy of each test state; then, when all the average energies meet the preset conditions, the final reaction path of the target chemical reaction is generated. In this way, quantum computing can accurately generate reaction paths and improve the computing speed, promoting the further development of quantum chemical simulation applications.

[0219] like Fig. 9As shown, taking the SN2 reaction of CH3Cl and Cl- as an example, the method provided by the embodiment of the present invention and the method of generating the reaction path by using FCI (Full Configuration Interaction) in the classical method, under the same conditions, i.e. the same chemical reaction, the same basis set, the same preset accuracy, freezing the same orbit, etc., the generated reaction path accuracy is roughly the same, which intuitively reflects the advantages of the chemical reaction path generation method provided by the embodiment of the present invention in terms of calculation speed and calculation accuracy. In classical calculation, using FCI for calculation is currently the most accurate calculation method, which not only needs to consider the dynamic correlation of electrons, but also needs to consider the calculation accuracy, and generates all Slater determinant expansions under a given basis set, however, Slater determinants, however, the number of Slater determinants depends exponentially on the number of electrons and orbitals, and it is reported that the largest CI calculation ever was for a system with 22 electrons in 22 orbital activity spaces, corresponding to an astonishing 497634306624 (5×10^11) Slater determinants, therefore, FCI is only effectively used for small and medium-sized molecules. The method provided in the embodiment of the present invention can overcome the quantum exponential wall and make up for the problem that the classical method cannot calculate large molecules, while ensuring the calculation accuracy.

[0220] See also Fig.10 , Fig.10 A schematic diagram of a device for generating a chemical reaction path based on quantum computing provided in an embodiment of the present invention, and Figure 2 Corresponding to the process shown, the device includes:

[0221] An acquisition module 1001 is used to obtain an expected reaction path based on a target chemical reaction, wherein the expected reaction path includes a number of target molecules;

[0222] A measuring module 1002 is used to prepare a test state corresponding to each target molecule and measure the average energy of each test state;

[0223] Generation module 1003 is used to generate a final reaction path of the target chemical reaction when all the average energies meet a preset condition, wherein the preset condition is a preset accuracy of the difference between the current average energy and the previous average energy measured for the same test state, and the final reaction path contains the target molecule corresponding to the test state whose average energy meets the preset condition.

[0224] Specifically, the device further includes:

[0225] A preparation module is used to prepare a test state corresponding to the molecule to be measured when there is an average energy that does not meet the preset condition among all the average energies, and return to the step of measuring the average energy of each of the test states until the average energy of the test state of the molecule to be measured meets the preset condition, wherein the molecule to be measured is a target molecule whose average energy in the test state does not meet the preset condition.

[0226] Specifically, the obtaining module 1001 includes:

[0227] An obtaining unit, used to obtain a target transition state of the target chemical reaction;

[0228] The first determining unit is used to determine the expected reaction path according to the target transition state.

[0229] Specifically, the obtaining unit includes:

[0230] A first acquisition subunit is used to obtain a functional form and a basis set for the target chemical reaction;

[0231] The second acquisition subunit is used to obtain the target transition state based on the initial guess of the transition state structure of the target chemical reaction using the functional form and the basis set.

[0232] Specifically, the first determination unit is specifically used to determine the expected reaction path according to the target transition state, the functional form and the basis set.

[0233] Specifically, the plurality of target molecules include reactants, products and the target transition state in the target chemical reaction.

[0234] Specifically, the measuring module 1002 includes:

[0235] A first acquisition unit, used to respectively acquire the orbital and the number of electrons of each of the target molecules, wherein the orbital includes the target orbital;

[0236] A second determination unit is used to determine the cluster operator of the fermion form of each target molecule based on the target orbital and the number of electrons of each target molecule;

[0237] The second acquisition unit is used to acquire, for each target molecule, a test state corresponding to the target molecule based on the cluster operator in the fermion form of the target molecule.

[0238] Specifically, the second determining unit includes:

[0239] An acquisition subunit, used for acquiring the Hartree-Fock state of each target molecule according to the target orbital and the number of electrons of each target molecule;

[0240] The determination subunit is used to determine the cluster operator and the number of excitation items of the fermion form of each target molecule according to a pre-selected assumption method and the Hartree-Fock state of the target molecule.

[0241] Specifically, the measurement module further includes:

[0242] A third acquisition unit is used to respectively acquire the fermion Hamiltonian corresponding to each of the target molecules;

[0243] A transformation unit, for transforming, for each target molecule, the fermion Hamiltonian corresponding to the target molecule into the Pauli Hamiltonian of the target molecule;

[0244] The measuring unit is used for constructing quantum circuits corresponding to each of the sub-items for each of the target molecules according to the sub-items, and measuring the average energy of the test state of the target molecule using the quantum circuit, wherein the sub-items are obtained by decomposing the Pauli Hamiltonian of the target molecule.

[0245] It can be seen that the present invention first obtains the expected reaction path based on the target chemical reaction; then prepares the test state corresponding to each target molecule and measures the average energy of each test state; then, when all the average energies meet the preset conditions, the final reaction path of the target chemical reaction is generated. In this way, quantum computing can accurately generate reaction paths and improve the computing speed, promoting the further development of quantum chemical simulation applications.

[0246] An embodiment of the present invention further provides a storage medium, in which a computer program is stored, wherein the computer program is configured to execute the steps of any of the above method embodiments when running.

[0247] Specifically, in this embodiment, the above storage medium may be configured to store a computer program for performing the following steps:

[0248] S201: obtaining an expected reaction path based on a target chemical reaction, wherein the expected reaction path includes a number of target molecules;

[0249] S202: preparing a test state corresponding to each target molecule respectively, and measuring the average energy of each test state;

[0250] S203: When all the average energies meet the preset conditions, a final reaction path of the target chemical reaction is generated, wherein the preset conditions are the preset accuracy of the difference between the current average energy and the previous average energy measured for the same test state, and the final reaction path contains the target molecules corresponding to the test state whose average energy meets the preset conditions.

[0251] Specifically, in this embodiment, the above-mentioned storage medium may include but is not limited to: a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and other media that can store computer programs.

[0252] It can be seen that the present invention first obtains the expected reaction path based on the target chemical reaction; then prepares the test state corresponding to each target molecule and measures the average energy of each test state; then, when all the average energies meet the preset conditions, the final reaction path of the target chemical reaction is generated. In this way, quantum computing can accurately generate reaction paths and improve the computing speed, promoting the further development of quantum chemical simulation applications.

[0253] An embodiment of the present invention further provides an electronic device, comprising a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0254] Specifically, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0255] Specifically, in this embodiment, the processor may be configured to perform the following steps through a computer program:

[0256] S201: obtaining an expected reaction path based on a target chemical reaction, wherein the expected reaction path includes a number of target molecules;

[0257] S202: preparing a test state corresponding to each target molecule respectively, and measuring the average energy of each test state;

[0258] S203: When all the average energies meet the preset conditions, a final reaction path of the target chemical reaction is generated, wherein the preset conditions are the preset accuracy of the difference between the current average energy and the previous average energy measured for the same test state, and the final reaction path contains the target molecules corresponding to the test state whose average energy meets the preset conditions.

[0259] It can be seen that the present invention first obtains the expected reaction path based on the target chemical reaction; then prepares the test state corresponding to each target molecule and measures the average energy of each test state; then, when all the average energies meet the preset conditions, the final reaction path of the target chemical reaction is generated. In this way, quantum computing can accurately generate reaction paths and improve the computing speed, promoting the further development of quantum chemical simulation applications.

[0260] The embodiments shown in the drawings explain in detail the structure, features and effects of the present invention. The above are only preferred embodiments of the present invention, but the present invention is not limited to the scope of implementation shown in the drawings. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the description and drawings, should be within the protection scope of the present invention.

Claims

1. A method for generating a chemical reaction path based on quantum computing, characterized in that: The method comprises: Based on the target chemical reaction, obtaining an expected reaction path, wherein the expected reaction path includes a number of target molecules; preparing a test state corresponding to each of the target molecules respectively, and measuring the average energy of each of the test states; When all the average energies meet the preset conditions, the final reaction path of the target chemical reaction is generated, wherein the preset conditions are the preset accuracy of the difference between the current average energy and the previous average energy measured for the same test state, and the final reaction path contains the target molecules corresponding to the test state whose average energy meets the preset conditions.

2. The method according to claim 1, characterized in that The method further comprises: When there is an average energy among all the average energies that does not satisfy the preset condition, prepare a test state corresponding to the molecule to be measured, and return to the step of measuring the average energy of each test state until the average energy of the test state of the molecule to be measured meets the preset condition, wherein the molecule to be measured is a target molecule whose average energy in the test state does not satisfy the preset condition.

3. The method according to claim 2, characterized in that The step of obtaining an expected reaction path based on a target chemical reaction includes: Obtaining a target transition state of the target chemical reaction; The expected reaction pathway is determined based on the target transition state.

4. The method according to claim 3, characterized in that The step of obtaining a target transition state of the target chemical reaction comprises: Obtaining a functional form and basis set for the target chemical reaction; Based on the initial guess of the transition state structure of the target chemical reaction, the target transition state is obtained using the functional form and the basis set.

5. The method according to claim 4, characterized in that Determining the expected reaction path according to the target transition state includes: The expected reaction pathway is determined based on the target transition state, the functional form and the basis set.

6. The method according to any one of claims 3 to 5, characterized in that: The plurality of target molecules include reactants, products and the target transition state in the target chemical reaction.

7. The method according to claim 6, characterized in that The step of preparing the test state corresponding to each target molecule comprises: Respectively obtaining the target orbital and the number of electrons of each of the target molecules; Determining a cluster operator of the fermion form of each of the target molecules based on the target orbital and the number of electrons of the target molecule; For each of the target molecules, based on the cluster operator in the fermion form of the target molecule, the test state corresponding to the target molecule is obtained.

8. The method according to claim 7, characterized in that The step of determining the cluster operator of the fermion form of each target molecule based on the target orbital and the number of electrons of the target molecule comprises: Obtaining the Hartree-Fock state of each target molecule according to the target orbital and the number of electrons of each target molecule; For each of the target molecules, the cluster operator and the number of excitation terms of the fermion form of the target molecule are determined according to a pre-selected assumption method and the Hartree-Fock state of the target molecule.

9. The method according to claim 8, characterized in that The measuring of the average energy of each test state comprises: Obtaining the fermion Hamiltonian corresponding to each of the target molecules respectively; For each target molecule, transform the fermion Hamiltonian corresponding to the target molecule into the Pauli Hamiltonian of the target molecule; For each of the target molecules, quantum circuits corresponding to the sub-items are constructed according to the sub-items, and the average energy of the test state of the target molecule is measured using the quantum circuits, wherein the sub-items are obtained by decomposing the Pauli Hamiltonian of the target molecule.

10. A device for generating a chemical reaction path based on quantum computing, characterized in that: The device comprises: An acquisition module, used to obtain an expected reaction path based on a target chemical reaction, wherein the expected reaction path includes a number of target molecules; A measurement module, used to prepare a test state corresponding to each target molecule and measure the average energy of each test state; A generation module is used to generate a final reaction path of the target chemical reaction when all the average energies meet a preset condition, wherein the preset condition is a preset accuracy of the difference between the current average energy and the previous average energy measured for the same test state, and the final reaction path contains the target molecule corresponding to the test state whose average energy meets the preset condition.

11. A storage medium, characterized in that: The storage medium stores a computer program, wherein the computer program is configured to execute the method according to any one of claims 1 to 9 when executed.

12. An electronic device comprising a memory and a processor, characterized in that: A computer program is stored in the memory, and the processor is configured to run the computer program to perform the method according to any one of claims 1 to 9.

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