Dft calculation model optimization method of vibration-electron interaction in x-type double helical configuration

Abstract

The application provides a DFT calculation model optimization method for vibration-electron interaction in X-type double-spiralene configuration, and belongs to the technical field of quantum chemistry multi-scale calculation; first, experimental data of X-type double-spiralene material is obtained through spectral technology, and microscopic detailed data is obtained through quantum chemistry DFT calculation, so that the energy barrier, vibration spectrum, electron cloud density and molecular orbital energy level data of the X-type double-spiralene material are obtained. For the molecular aggregate state, the periodic DFT and molecular mechanics MM coupling method is used, the active area is described by DFT, and the weak interaction area is processed by MM, and the periodic characteristics of the energy band structure are calculated based on the mixed precision calculation framework. The multi-scale coupled DFT algorithm is used to correlate the vibration-electron interaction at the atomic scale with the energy band structure, non-radiative transition and other mesoscopic characteristics of the molecule, and the macroscopic photoelectric characteristics of the material are output, so that the calculation closed loop from the micro to the macro is completed.

Description

Technical Field

[0001] This invention belongs to the field of quantum chemical multiscale computation technology, and particularly relates to a DFT computation model optimization method for vibrational-electronic interactions in X-type dihexene configuration. Background Technology

[0002] X-type dihexenes are chiral organic functional materials with a specific molecular configuration. Their core characteristic lies in their superior optoelectronic properties achieved through a non-planar helical framework and multiple resonance effects. Taking borazine-based dihexenes as an example, the steric hindrance generated by the helical arrangement suppresses racemization, resulting in a maximum absorption asymmetry factor (gabs) of 0.033 (502 nm), the highest value in the visible light region. The introduction of push-pull electron effects by heteroatoms (such as NBN units) causes a redshift in the absorption spectrum to 300-700 nm and achieves a narrow emission half-width (FWHM) (22-24 nm). Changes in molecular vibrational modes directly affect configurational stability and electronic transition efficiency. X-type dihexenes have significant research value in chiral optoelectronic materials (such as OLEDs and bioimaging) and spintronics.

[0003] The photoelectric properties of X-type dihexenes are determined by multiple factors, including vibrational dynamics, electron cloud distribution, and orbital energy levels. Existing methods often rely on single types of data (such as predicting band structures using only molecular orbital energy levels), making it difficult to fully capture the complex structure-property relationships.

[0004] Traditional DFT calculations often separate "configurational stability, band structure, and nonradiative transition rates" into independent tasks, neglecting their intrinsic interrelationships. For example, changes in molecular vibrational modes can simultaneously affect configurational stability and electronic transition efficiency; isolated calculations can easily lead to error accumulation and fail to accurately reflect the true properties of the material.

[0005] The application performance of X-type dihexene (such as macroscopic luminescence efficiency and conductivity) is essentially determined by the vibrational modes and electronic behavior at the atomic scale. Traditional calculation methods cannot establish the relationship between the atomic scale, mesoscopic structure, and macroscopic properties.

[0006] It is easy for microscopic calculation results to become disconnected from macroscopic experimental data.

[0007] As a highly conjugated chiral molecule, X-type dihexene has a large number of atoms in its system. If full-precision DFT calculation is used, it will face problems of excessively high computational cost and long time consumption. If the precision is simply reduced, the reliability of the results will decrease. Theoretical research needs to consider the balance of costs.

[0008] In summary, X-type dihexene suffers from several pain points in theoretical calculations, including "multi-task isolation, multi-scale discontinuity, and an imbalance between accuracy and efficiency." Summary of the Invention

[0009] To address the above problems, this invention proposes a DFT calculation model optimization method for vibrational-electronic interactions in the X-type dihexene configuration, comprising the following steps:

[0010] S1. First, experimental data of X-type dihexene material is obtained through spectroscopic techniques, and microscopic fine data is obtained through quantum chemical DFT calculations. The energy barrier, vibrational spectrum, electron cloud density, and molecular orbital energy level data of X-type dihexene material are obtained by combining these methods.

[0011] S2, using vibrational spectra and electron cloud density data to calculate energy barriers and vibrational characteristics, defines the configurational stability of X-type dihexene;

[0012] Perform band structure prediction analysis on X-type dihexene; based on molecular orbital energy level data, calculate the band structure composed of band diagram, band gap value, and the contribution ratio of molecular orbitals to the band.

[0013] Nonradiative transition analysis of X-type dihexene was performed; electronic state energy difference, transition dipole moment, orbital distribution, and equilibrium geometry of excited and ground states were obtained by time-dependent density functional theory (TD-DFT) calculations.

[0014] S3, Multiscale Coupled DFT Calculation of the Photoelectric Properties of X-type Dihexene Materials: Using energy barrier, vibrational spectrum, electron cloud density, and molecular orbital energy level data as microscopic fine data, and configurational stability, molecular band structure, and nonradiative transitions as mesoscopic data, the vibrational-electronic coupling quantization model and charge-band mapping model are used as calculation rules to calculate the radiative and nonradiative transition rates of X-type dihexene. The ratio of the radiative and nonradiative transition rates is the luminous efficiency, a macroscopic property parameter characterizing the material.

[0015] Preferably, the specific process of S1 is as follows:

[0016] This study constructed a dataset of energy barriers, vibrational spectra, electron cloud density, and molecular orbital energy levels for X-type dihexene materials. X-type dihexene crystals with a purity greater than 98% were prepared into a solution, which was then spin-coated into a solid film and grown as single crystals for testing. Energy barrier data acquisition involved selecting an X-type dihexene molecular model, optimizing the initial ground-state configuration using density functional theory (DFT), determining the torsional path of the helical arms and the deformation path of the bond angles at the cross points that affect configuration stability, setting scan variables and step sizes to generate potential energy surface curves, and determining the difference between the transition state energy and the initial state energy from the potential energy surface curves to obtain the energy barrier of the target deformation path. Vibrational spectral data acquisition involved Raman spectroscopy to collect the torsional vibrational peaks of the X-type dihexene solution, smoothing the spectra, and labeling the peak positions, intensities, and full width at half maximum (FWHM) of characteristic peaks. Theoretical vibrational spectra were generated based on DFT calculations, and the experimental peak positions were matched with the theoretical peak positions. Electron cloud density acquisition involved obtaining high-precision electron cloud data through DFT calculations. The B97X-D / def2-TZVP functional basis set outputs wavefunction files and generates electron cloud density isosurface maps; molecular orbital energy level data acquisition uses ultraviolet photoelectron spectroscopy to test the photoelectron emission signal of X-type dihexene solid films, calculates the vacuum energy level through the secondary electron cutoff edge, and obtains the absolute energy level by combining it with the binding energy of the valence band top; and outputs the energy values ​​and wavefunctions of HOMO, LUMO, and nearest neighbor orbitals through DFT calculation.

[0017] Preferably, the definition of the configurational stability of X-type dihexene specifically includes:

[0018] Energy barriers and vibrational characteristics were calculated using vibrational spectra, electron cloud density, and other data. A configuration of X-type dihexene was determined to be highly stable if it met the following criteria: energy barrier > 20 kJ / mol, vibration without imaginary frequencies, and torsional frequency > 100 cm⁻¹. A configuration of X-type dihexene was determined to be moderately stable if it met the following criteria: energy barrier > 20 kJ / mol, vibration without imaginary frequencies, and torsional frequency > 100 cm⁻¹. A configuration of X-type dihexene was determined to be unstable if it did not meet the following criteria: energy barrier > 20 kJ / mol, vibration without imaginary frequencies, and torsional frequency > 100 cm⁻¹.

[0019] Preferably, S2 performs X-type dihexene band structure prediction analysis, specifically: based on molecular orbital energy level data, output the initial band distribution; define the low-precision layer, medium-precision layer, and high-precision layer judgment conditions of the mixed precision calculation framework and propose corresponding band gap calculation methods; the band structure consists of the band diagram, band gap value, and the contribution ratio of molecular orbitals to the band, with HOMO contribution ≥ 60% up to the valence band top.

[0020] Preferably, the nonradiative transition analysis of X-type dihexene in S2 specifically involves: calculating the electronic state energy difference, transition dipole moment, orbital distribution, and equilibrium geometry of excited and ground states using time-dependent density functional theory (TD-DFT); defining an active vibrational mode as one where the vibrational frequency, atomic motion direction, and HT coupling constant all satisfy the judgment conditions; and calculating the transition rate of the active mode based on the vibration-electron coupling strength and the Fermi golden rule.

[0021] Preferably, the S3 process specifically includes:

[0022] S31, extraction of atomic-scale microstructure information; using the energy barrier, vibrational spectrum, electron cloud density, and molecular orbital energy level data of X-type dihexene collected by S1 as a standardized set of micro parameters;

[0023] S32, cross-scale correlation algorithm modeling; combined vibration-electronic coupling quantization model and charge-band mapping model, to calculate the mesoscopic properties of X-type dihexene;

[0024] (1) Vibration-electronic coupling quantification model: based on the lowest excited state of X-type dihexene and ground state The overlap integral of the vibration wave function is the FC factor, with express:

[0025]

[0026] Must meet ;

[0027] Using Herzberg-Taylor HT coupling constant Describe the effect of the a-th vibrational mode on electronic transitions.

[0028]

[0029] In the formula These are the canonical coordinates of vibration mode a. It is a reduction of quality. It is the angular frequency of vibration. It is the Hamiltonian; HT coupling constant. Must meet ;

[0030] The weighting ratio of the coupling weight in the spiral torsion mode is ≥40%, and the ratio of the C=C scaling mode is ≥30%.

[0031] (2) Charge-band mapping model: the electron cloud density at the atomic scale The initial boundary conditions used for mesoscopic calculations satisfy the Poisson equation, expressed as follows:

[0032]

[0033] In the formula Represents electrostatic potential, Represents the vacuum permittivity. ; to electrostatic potential The periodic DFT calculation using VASP software was introduced to correct the lattice potential function, so that the deviation between the mesoscopic valence band top VBM and the atomic-scale HOMO level is <0.2 eV, and the deviation between the conduction band bottom CBM and the LUMO level is <0.2 eV.

[0034] S33, Derivation of macroscopic photoelectric properties; Based on mesoscopic property data, the macroscopic performance parameter luminous efficiency is output through the carrier mobility formula and the luminous efficiency formula.

[0035] Radiative transition rate, in This indicates that the following calculation expression is satisfied:

[0036]

[0037] in Let be Planck's constant. For the transition frequency, For the transition dipole moment, Denotes the reduced Planck constant. Represents the speed of light in a vacuum. ;

[0038] Nonradiative transition rate Represented as:

[0039]

[0040] In the formula Let ∑ denote the reduced Planck constant. This represents the summation over all strongly coupled active vibrational modes. This represents the square of the HT coupling constant. Represents the FC factor. exist The vibrational dynamic density at a given location is obtained by accumulating the energy distribution of the S0 state vibrational modes. This indicates the temperature-dependent Boltzmann factor;

[0041] Luminous efficiency Satisfy the following expression:

[0042]

[0043] In the formula Indicates the radiative transition rate. This represents the nonradiative transition rate.

[0044] Preferably, the X-type dihexene band structure prediction analysis specifically includes the following process:

[0045] Based on the collected molecular orbital energy level data, including molecular orbital energy levels and wave functions, HOMO and LUMO energies and nearest neighbor orbital distributions;

[0046] The criteria for determining the low-precision, medium-precision, and high-precision layers of the mixed-precision computation framework are defined as follows: The low-precision layer must satisfy a helical cross angle θ = 60°~90° and a HOMO-LUMO energy level difference E_g^mol = 2.5~3.5 eV; the medium-precision layer must satisfy a π-π stacking distance d = 3.3~3.8 Å and an intermolecular coupling energy V = 0.01~0.1 eV; the high-precision layer must satisfy a band diagram showing a continuous energy-wave vector relationship and having a clearly defined valence band top and conduction band bottom.

[0047] The bandgap calculation method of the mixed-precision calculation framework is defined as follows: the low-precision layer uses the GFN2-xTB semi-empirical method to construct a 2×2×1 periodic supercell; the medium-precision layer uses the PBE0-D3 / def2-SVP DFT method to optimize the molecular configuration within the supercell and map the single-molecule HOMO / LUMO energy levels to aggregated state orbitals; the high-precision layer uses the GW method to correct the valence band top and conduction band bottom energies.

[0048] Preferably, the defined vibrational frequency, atomic motion direction, and HT coupling constant all satisfy the judgment condition for an active vibrational mode, specifically:

[0049] Vibration frequency satisfy:

[0050]

[0051] In the formula, h represents Planck's constant, and n represents a constant with a range of [1,3].

[0052] Direction of atomic motion and → The geometric configurations are consistent;

[0053] The lowest excited state based on X-type dihexene and ground state The overlap integral of the vibration wave function is the FC factor, with express:

[0054]

[0055] Must meet ;

[0056] The coupling constant is represented by Herzberg-Taylor (HT). Describe the effect of the a-th vibrational mode on electronic transitions:

[0057]

[0058] In the formula These are the canonical coordinates of vibration mode a. It is a reduction of quality. It is the angular frequency of vibration. It is the Hamiltonian; HT coupling constant. Must meet .

[0059] Compared with the prior art, the present invention has the following innovative features:

[0060] (1) Multi-task joint solution method: Unlike traditional single-task calculation, this method integrates configuration stability analysis, band structure prediction, and nonradiative transition rate calculation into the same framework. Molecular vibrational modes are inferred from vibrational spectral data, and the structural stability of molecules is determined by combining electron cloud density distribution. Molecular orbital energy level data are used in combination with a mixed-precision calculation framework to predict the electronic band distribution of materials. Based on the vibration-electron interaction mechanism, vibrational modes are correlated with electronic transition processes to efficiently solve for nonradiative transition rates.

[0061] (2) Hybrid precision calculation framework: Collect multi-modal and multi-dimensional data such as energy barrier, vibrational spectrum, electron cloud density, and molecular orbital energy level. High precision calculation is used for key atomic regions to ensure accuracy, while low precision calculation is used for non-key regions to improve efficiency. Adaptive basis optimization and pseudopotential calibration are used to maintain calculation consistency.

[0062] (3) Multiscale Coupled DFT: The multiscale coupled DFT algorithm realizes cross-dimensional calculation, calculates the energy barrier, vibration mode, electron cloud density and molecular orbital energy level of molecules, obtains microstructure information, and associates the vibration-electron interaction at the atomic scale with the mesoscopic properties such as the energy band structure and nonradiative transition of molecules through the algorithm, and finally outputs the macroscopic photoelectric properties of materials (such as luminous efficiency and conductivity), completing the calculation closed loop from micro to macro.

[0063] The beneficial effects brought about by the innovation of this invention include:

[0064] (1) Improve computational accuracy: Based on the structural characteristics of X-type dihexene, the three core research objectives are integrated into the same framework, avoiding the accumulation of errors from separate task calculations;

[0065] (2) Improved computational efficiency: High-precision calculation is used for critical atomic regions to ensure accuracy, while low-precision calculation is used for non-critical regions to improve efficiency, thus balancing computational accuracy and speed;

[0066] (3) Wide range of applicable scenarios: It is applicable to the joint study of atomic, mesoscopic and macroscopic properties of X-type dihexene, and is not for parameter tuning of a single material. Attached Figure Description

[0067] Figure 1 This is a flowchart illustrating the overall technical process of the present invention.

[0068] Figure 2 This is a diagram showing the energy interaction relationship between molecular orbital energy levels in this invention.

[0069] Figure 3 This is a comparison chart of the efficiency of the hybrid precision computing framework of this invention.

[0070] Figure 4 This is a schematic diagram of the electronic transition principle of the present invention. Detailed Implementation

[0071] This invention proposes an optimization method for the vibrational-electron interaction density functional theory (DFT) calculation model of the X-type dihexene configuration. The overall technical path is as follows: Figure 1 As shown:

[0072] S1. A dataset of energy barriers, vibrational spectra, electron cloud density, and molecular orbital energy levels for X-type dihexene materials was constructed. X-type dihexene crystals with a purity greater than 98% were prepared into a solution, which was then spin-coated into a solid film and grown as single crystals as test samples. Energy barrier data acquisition involved selecting an X-type dihexene molecular model, optimizing the initial ground-state configuration using density functional theory (DFT), determining the torsional path of the helical arms and the deformation path of the bond angles at the cross points that affect configuration stability, setting scan variables and step sizes to generate potential energy surface curves, and determining the difference between the transition state energy and the initial state energy from the potential energy surface curves to obtain the energy barrier of the target deformation path. Vibrational spectral data acquisition involved Raman spectroscopy to collect the torsional vibrational peaks of the X-type dihexene solution, smoothing the spectrum, and labeling the peak positions, intensities, and full width at half maximum (FWHM) of characteristic peaks. Theoretical vibrational spectra were generated based on DFT calculations, and the experimental peak positions were matched with the theoretical peak positions by comparison. Electron cloud density acquisition involved obtaining high-precision electron cloud data through DFT calculations. The B97X-D / def2-TZVP functional basis set outputs wavefunction files, generating electron cloud density isosurface maps. Molecular orbital energy level data is acquired by measuring the photoelectron emission signal of the X-type dihexene solid film using ultraviolet photoelectron spectroscopy. The vacuum energy level is calculated through the secondary electron cutoff edge, and combined with the binding energy at the valence band top, the absolute energy level is obtained. DFT calculations are then performed to output the energy values ​​and wavefunctions of the HOMO, LUMO, and nearest-neighbor orbitals.

[0073] S2 defines a method for analyzing the configurational stability of X-type dihexenes. Energy barriers and vibrational characteristics are calculated using vibrational spectra and electron cloud density data. If the energy barrier is >20 kJ / mol and the vibrations have no imaginary frequencies and the torsional frequency is >100 cm⁻¹, the X-type dihexene configuration is classified as highly stable. If the energy barrier is >20 kJ / mol or the vibrations have no imaginary frequencies and the torsional frequency is >100 cm⁻¹, the X-type dihexene configuration is classified as moderately stable. If the energy barrier is not >20 kJ / mol and the vibrations do not have imaginary frequencies and the torsional frequency is not >100 cm⁻¹, the X-type dihexene configuration is classified as unstable.

[0074] S3 defines a method for predicting and analyzing the band structure of X-type dihexenes; based on molecular orbital energy level data, it outputs the initial band distribution. It defines the criteria for low-precision, medium-precision, and high-precision layers in a mixed-precision calculation framework and proposes corresponding band gap calculation methods. The band structure consists of the band diagram, band gap value, and the contribution percentage of molecular orbitals to the band (HOMO contribution ≥ 60% up to the valence band top).

[0075] S4 defines a nonradiative transition analysis method for X-type dihexenes; calculations are performed using time-dependent density functional theory (TD-DFT) (e.g.) The electronic state energy difference, transition dipole moment, orbital distribution, and equilibrium geometry of the excited and ground states are obtained using B97X-D. A vibrational mode is defined as active if its vibrational frequency, atomic motion direction, and HT coupling constant all satisfy the criteria. The transition rate of the active mode is calculated based on the vibrational-electron coupling strength and the Fermi golden rule.

[0076] S5 uses multi-scale coupled DFT to calculate the photoelectric properties of X-type dihexene materials. It calculates the energy barrier, vibrational spectrum, electron cloud density, and molecular orbital energy levels of the molecules to obtain microstructural information. Through algorithms, it correlates the vibrational-electron interactions at the atomic scale with the band structure and mesoscopic characteristics of nonradiative transitions of the molecules, and outputs the luminous efficiency that expresses the macroscopic photoelectric properties of the material.

[0077] S1. Constructing a dataset of vibrational spectra, electron cloud density, and molecular orbital energy levels for X-type dihexene materials:

[0078] X-type dihexene crystals with a purity greater than 98% were prepared into a solution and spin-coated into a solid film. Experimental data of the X-type dihexene material were obtained using spectroscopic techniques, and detailed microscopic data were acquired through quantum chemical DFT calculations. These combined methods yielded data on the energy barrier, vibrational spectrum, electron cloud density, and molecular orbital energy levels of the X-type dihexene material. The specific processing steps included:

[0079] S1-1, Prepare a dihexene solution phase reagent and spin-coat it into a solid film. The specific steps are as follows:

[0080] (1) The purity of the X-type dispirene raw material was determined by high performance liquid chromatography (HPLC). Samples with a purity ≥98% were screened and dissolved in dichloromethane, chloroform or toluene at a concentration of 0.5~5 mg / mL. The dissolution was promoted by magnetic stirring (300 rpm, 30 min) and sonication (300 W, 15 min). The solution phase X-type dispirene was then filtered through a 0.22 μm organic phase filter.

[0081] (2) A thin film with a thickness of 50~100nm was spin-coated with X-type bispirene in solution phase and used as a solid sample for testing.

[0082] (3) Cultivate single crystals of X-type bispirene in solution phase and use them as crystal samples for testing.

[0083] S1-2, Collect energy barrier data for X-type dihexene materials. The specific steps are as follows:

[0084] (1) DFT optimization uses long-range corrected functionals The B97X-D incorporates the all-electronic basis set def2-TZVP and introduces D3 dispersion correction; the convergence threshold is energy < 1 × 10⁻⁶. -6 au, force < 1×10 -3 au / Å; the key geometric parameters include the helical cross angle (θ, the angle between the axes of the two helical arms), the CC bond length at the cross point (d), and the dihedral angle of the conjugate ring (φ).

[0085] (2) The scanning variable for the spiral arm torsion path is the spiral intersection angle θ, and the scanning range is the initial optimized value ±30°; the scanning variable for the intersection point bond angle deformation path is the CCC bond angle (α), and the scanning range is the initial optimized value ±15°.

[0086] (3) The scanning step size is set as follows: the step size of the spiral cross angle θ is 0.5°~2° (when θ is close to the initial value, take a small step size), and the step size of the bond angle α is 0.5°~1°. Each scan keeps the other geometric parameters except variables free to optimize, calculates the single-point energy and records the configuration coordinates.

[0087] (4) The energy barrier is the difference between the highest energy point (transition state) and the initial energy in the potential energy surface curve.

[0088] S1-3, Collect vibrational spectral data of X-type dihexene materials. The specific steps are as follows:

[0089] (1) The solution phase X-type dihexene was injected into the KBr window liquid cell (optical path 0.1 mm), and the background spectrum was obtained by scanning the blank solvent. The sample spectrum was tested by FT-IR spectrometer with parameters set to wavenumber 400~4000 cm⁻¹, resolution 4 cm⁻¹, and 64 scans. The ambient temperature and humidity were recorded simultaneously.

[0090] (2) Using Gaussian 16 software, the B3LYP-D3 functional (considering dispersion) and def2-SVP basis set were selected to optimize the ground state configuration of the X-type dihexene. The convergence threshold was set to energy < 1 × 10⁻ 6 au, force < 1×10 - ³a.u. / Å. The Hessian matrix was calculated based on the optimized configuration, and the vibrational frequencies (corrected for systematic errors by a correction factor of 0.96–0.98), infrared intensity, and Raman activity were output. The calculation results were converted into theoretical spectra using Origin software, and the wavenumber range was consistent with experimental measurements.

[0091] S1-4, Collect electron cloud density data of X-type dihexene materials. The specific steps are as follows:

[0092] (1) Using Gaussian 16 quantum chemistry software, select the long-range calibration functional. B97X-D (electron delocalization adapted to conjugated systems) and the all-electron basis set def2-TZVP (precisely describing valence electron distribution) are used to optimize the ground-state geometry of X-type dihexenes. The convergence threshold is set to: energy < 1 × 10⁻⁶. -6 au, gradient force < 1×10 -3 au / Å ensures that the configuration is at the potential energy minimum.

[0093] (2) Based on the optimized configuration, calculate and output the wave function file, which includes molecular orbital coefficients, electron density matrix and basis set information; if environmental effects need to be simulated, the polarized continuum model (PCM) is added to the solution phase calculation, and the periodic boundary condition (PBC) is used for the solid phase calculation.

[0094] (3) Use Multiwfn software to load the wave function file, generate an electron cloud density isosurface map (isosurface value 0.02e / ų, reflecting the distribution of valence electrons), and output the three-dimensional grid data of the electron cloud density of the whole molecule (step size 0.1Å).

[0095] S1-5, Collect molecular orbital energy level data of X-type dihexene materials. The specific steps are as follows:

[0096] (1) Using Gaussian 16 quantum chemistry software, select the long-range calibration functional. B97X-D (electron delocalization adapted to helical conjugated systems) and the all-electron basis set def2-TZVP were used to optimize the ground-state configuration of X-type dihexenes. The convergence threshold was set to: energy < 1 × 10⁻⁶. -6 au, gradient force < 1×10 -3au / Å ensures that the configuration is at the potential energy surface minimum.

[0097] (2) Based on the optimized configuration, calculate the molecular orbital energies. The energy interactions of the molecular orbital levels are as follows: Figure 2 As shown. Output the energy values ​​(unit: eV) of HOMO, LUMO and neighboring orbits (HOMO-1, HOMO-2, LUMO+1, LUMO+2), with an accuracy controlled within ±0.01 eV.

[0098] Figure 2 In the context of strong sp mixing, it refers to the phenomenon where s orbitals and p orbitals undergo strong mixing when atomic orbitals have similar energies and matching symmetry.

[0099] Weak sp mixing refers to the interaction between the s orbitals and p orbitals of an atom due to their similar energies, but the degree of mixing is relatively weak.

[0100] B2 represents the expression of a homonuclear diatomic molecule of boron;

[0101] C2 represents the expression of a carbon homonuclear diatomic molecule;

[0102] N2 represents the expression of a homonuclear diatomic molecule of nitrogen;

[0103] O2 represents the expression of a homonuclear diatomic molecule of oxygen;

[0104] F2 represents the expression of a homonuclear diatomic molecule of fluorine;

[0105] Ne2 represents the expression of a homonuclear diatomic molecule of neon;

[0106] σ2s represents the σ-type bonding molecular orbital, which is formed by the overlap of the 2s energy level orbitals of two atoms in a "head-to-head" manner, and is the lowest energy bonding orbital;

[0107] σ2s* represents the σ-type antibonding molecular orbital, which is formed by the overlap of the 2s energy level orbitals of two atoms in a "head-to-head" manner. It belongs to the higher energy antibonding orbitals.

[0108] π2p represents the π-type bonding molecular orbital, which is a low-energy orbital formed by the overlapping of the 2p energy level orbitals of two atoms in a "side-by-side" manner, and has an enhancing effect on molecular bonding.

[0109] σ2p represents the σ-type bonding molecular orbital, which is formed by the overlap of the 2p energy level orbitals of two atoms in a "head-to-head" manner. It is an orbital with lower energy and can significantly enhance the bonding between atoms.

[0110] π*2p represents a π-type antibonding molecular orbital, which is a higher-energy antibonding orbital formed by the overlap of the 2p energy level orbitals of two atoms in a "side-by-side" manner;

[0111] σ2p* represents the σ-type bonding molecular orbital, which is a higher-energy antibonding orbital formed by the overlap of the 2p energy level orbitals of two atoms in a "head-to-head" manner.

[0112] S2. Define the method for analyzing the configurational stability of X-type dihexenes:

[0113] S2-1, based on the energy barrier data collected in S1-2, the threshold is determined to be >20kJ / mol.

[0114] S2-2, Based on the vibration spectrum data collected in S1-3, the threshold is determined to be vibration without imaginary frequencies and torsional frequency > 100 cm⁻¹. The specific steps are as follows:

[0115] (1) Compare the experimental spectra in steps S1-3 with the theoretical spectra, and determine the vibration modes corresponding to each characteristic peak by matching the peak position deviation (<5 cm⁻¹ is considered reliable) and intensity trend. The strong peak at 1600-1650 cm⁻¹ corresponds to the C=C stretching vibration of the helical conjugate skeleton, the peak at 800-900 cm⁻¹ corresponds to the CH out-of-plane bending vibration on the ring, and the weak peak at 300-500 cm⁻¹ corresponds to the torsional vibration of the helical arm.

[0116] (2) Calculate the Hessian matrix based on the optimized configuration and output all vibration frequencies and modes; if all vibration frequencies are positive (no imaginary frequencies), it is determined to be mechanically stable; focus on extracting the torsional vibration of the helical arm (300~600cm). -1 ) and skeletal stretching vibration (1500~1650cm) -1 The frequency of the torsional frequency is determined by the condition that it is greater than 100 cm⁻¹. -1 The amplitude of the skeletal bond length vibration is <0.02Å.

[0117] S2-3 defines the configurational stability of X-type dihexene materials. Materials meeting the following conditions are considered highly stable: an energy barrier > 20 kJ / mol, vibrations without imaginary frequencies, and a torsional frequency > 100 cm⁻¹. Materials meeting these conditions are moderately stable: an energy barrier > 20 kJ / mol, vibrations without imaginary frequencies, and a torsional frequency > 100 cm⁻¹. Materials not meeting these conditions are considered unstable.

[0118] S3. Define a method for predicting and analyzing the band structure of X-type doubly helicenes:

[0119] S3-1, based on the molecular orbital energy level data collected in S1-5, including molecular orbital energy levels and wave functions, HOMO and LUMO energies and nearest neighbor orbital distributions;

[0120] S3-2 defines the criteria for determining the low-precision, medium-precision, and high-precision layers in the mixed-precision computation framework. The low-precision layer must satisfy a helical cross angle θ = 60°~90° and a HOMO-LUMO energy level difference E_g^mol = 2.5~3.5 eV; the medium-precision layer must satisfy a π-π stacking distance d = 3.3~3.8 Å and an intermolecular coupling energy V = 0.01~0.1 eV; the high-precision layer must satisfy a band diagram showing a continuous energy-wave vector (Ek) relationship and the existence of a clearly defined valence band top (VBM) and conduction band bottom (CBM).

[0121] S3-3 defines the bandgap calculation method for a mixed-precision computational framework. The low-precision layer uses the GFN2-xTB semi-empirical method to construct a 2×2×1 periodic supercell; the medium-precision layer uses the PBE0-D3 / def2-SVP DFT method to optimize the intracellular molecular configuration, mapping single-molecule HOMO / LUMO energy levels to aggregated state orbitals; the high-precision layer uses the GW method to correct the valence band top (VBM) and conduction band bottom (CBM) energies. The efficiency comparison of the mixed-precision computational framework is as follows: Figure 3 As shown.

[0122] S4. Define the nonradiative transition analysis method for X-type dihexenes:

[0123] S4-1, calculated via TD-DFT (e.g.) B97X-D / def2-TZVP) determined the lowest excited state of X-type dihexene (in terms of...). (representation) and ground state (in terms of) (Represented). The electronic state energy difference, transition dipole moment, orbital distribution, and equilibrium geometry of the excited and ground states are calculated. The electronic state energy difference is expressed as... express,

[0124]

[0125] In the formula This represents the energy of the lowest excited state. This represents the energy of the ground state. Vibrational spectral data are obtained from S1-3, with a frequency range of 200~1800 cm⁻¹.

[0126] S4-2, if the vibrational frequency, atomic motion direction, FC factor, and HT coupling constant all satisfy the following conditions, it is defined as an active vibrational mode. The electronic transition principle diagram is as follows: Figure 4 As shown.

[0127] Vibration frequency (in) (Indicates) that:

[0128]

[0129] In the formula, h represents Planck's constant, and n represents a constant ranging from [1, 3]. The direction of atomic motion is related to... → The geometric configurations are consistent.

[0130] Based on the lowest excited state of X-type dihexene (with (representation) and ground state (in terms of) The overlap integral of the vibration wave function (represented by) is the FC factor. express:

[0131]

[0132] Must meet .

[0133] Using Herzberg-Taylor (denoted by HT) coupling constant (in (represented by) describes the effect of the a-th vibrational mode on electronic transitions.

[0134]

[0135] In the formula These are the canonical coordinates of vibration mode a. It is a reduction of quality. It is the angular frequency of vibration. It is the Hamiltonian. HT is the coupling constant. Must meet .

[0136] S4-3, based on vibration-electronic coupling strength and combined with Fermi's golden rule, yields the formula for the nonradiative transition rate. The nonradiative transition rate... It can be represented as

[0137]

[0138] In the formula Let ∑ denote the reduced Planck constant. This represents the summation over all strongly coupled active vibrational modes. This represents the square of the HT coupling constant (characterizing the coupling strength weight). This represents the FC factor (characterizing the degree of overlap of vibrational wave functions). exist The vibrational dynamic density (unit: eV⁻¹) at a given location is obtained by summing the energy distribution of the S0 state vibrational modes. This indicates the temperature-dependent Boltzmann factor.

[0139] S5. Calculation of photoelectric properties of X-type dihexene materials using multi-scale coupled DFT:

[0140] The system collects fundamental parameters of vibration and electronic structure to provide quantitative input for cross-scale correlation; establishes a quantitative mapping between atomic-scale parameters and mesoscopic properties to achieve cross-dimensional information transfer; and transforms mesoscopic properties into macroscopic measurable parameters to complete the computational closed loop.

[0141] S5-1, extraction of atomic-scale microstructure information; using the energy barrier, vibrational spectrum, electron cloud density, and molecular orbital energy level data of X-type dihexene collected in S1 as a standardized set of microscopic parameters.

[0142] S5-2, Construction of cross-scale correlation algorithm; Through vibration-electron coupling quantization model and charge-band mapping model, atomic-scale parameters are correlated with mesoscopic properties to achieve cross-dimensional information transmission;

[0143] (1) Vibration-electronic coupling quantification model; based on the lowest excited state of X-type dihexene (with (representation) and ground state (in terms of) The overlap integral of the vibration wave function (represented by) is the FC factor. express:

[0144]

[0145] Must meet .

[0146] Using Herzberg-Taylor (denoted by HT) coupling constant (in (Representation) Describes the effect of the a-th vibrational mode on electronic transitions:

[0147]

[0148] In the formula These are the canonical coordinates of vibration mode a. It is a reduction of quality. It is the angular frequency of vibration. It is the Hamiltonian. HT is the coupling constant. Must meet .

[0149] The weighting of the spiral twist mode is ≥40%, and the weighting of the C=C stretch mode is ≥30%.

[0150] (2) Charge-band mapping model; the electron cloud density at the atomic scale (in terms of...) (represented) as the initial boundary conditions for mesoscopic calculations, using the Poisson equation:

[0151]

[0152] In the formula Represents electrostatic potential, Represents the vacuum permittivity. ; to electrostatic potential The periodic DFT calculation using VASP software was introduced to correct the lattice potential function, so that the deviation between the mesoscopic valence band top (VBM) and the atomic-scale HOMO level is <0.2 eV, and the deviation between the conduction band bottom (CBM) and the LUMO level is <0.2 eV.

[0153] S5-3, Derivation of macroscopic photoelectric properties: Based on mesoscopic property data, the macroscopic performance parameter luminous efficiency is output through the carrier mobility formula and the luminous efficiency formula.

[0154] Radiative transition rate, in This indicates that the following calculation expression is satisfied:

[0155]

[0156] in Let be Planck's constant. For the transition frequency, For the transition dipole moment, Denotes the reduced Planck constant. Represents the speed of light in a vacuum. .

[0157] Nonradiative transition rate It can be represented as:

[0158]

[0159] In the formula Let ∑ denote the reduced Planck constant. This represents the summation over all strongly coupled active vibrational modes. This represents the square of the HT coupling constant (characterizing the coupling strength weight). This represents the FC factor (characterizing the degree of overlap of vibrational wave functions). exist The vibrational dynamic density (unit: eV⁻¹) at a given location is obtained by summing the energy distribution of the S0 state vibrational modes. This indicates the temperature-dependent Boltzmann factor.

[0160] Luminous efficiency (in) (This indicates that) satisfies the following expression:

[0161]

[0162] In the formula Indicates the radiative transition rate. This represents the nonradiative transition rate.

[0163] The described embodiments are merely preferred embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

[0164] While the specific embodiments of the present invention have been described above, they are not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for optimizing the DFT calculation model of vibrational-electronic interactions in X-type dihexene configuration, characterized in that, Includes the following processes: S1. First, experimental data of X-type dihexene material is obtained through spectroscopic techniques, and microscopic fine data is obtained through quantum chemical DFT calculations. The energy barrier, vibrational spectrum, electron cloud density, and molecular orbital energy level data of X-type dihexene material are obtained by combining these methods. S2, using vibrational spectra and electron cloud density data to calculate energy barriers and vibrational characteristics, defines the configurational stability of X-type dihexene; Perform band structure prediction analysis on X-type dihexene; based on molecular orbital energy level data, calculate the band structure composed of band diagram, band gap value, and the contribution ratio of molecular orbitals to the band. Nonradiative transition analysis of X-type dihexene was performed; electronic state energy difference, transition dipole moment, orbital distribution, and equilibrium geometry of excited and ground states were obtained by time-dependent density functional theory (TD-DFT) calculations. S3, Multiscale Coupled DFT Calculation of the Photoelectric Properties of X-type Dihexene Materials: Using energy barrier, vibrational spectrum, electron cloud density, and molecular orbital energy level data as microscopic fine data, and configurational stability, molecular band structure, and nonradiative transitions as mesoscopic data, the vibrational-electronic coupling quantization model and charge-band mapping model are used as calculation rules to calculate the radiative and nonradiative transition rates of X-type dihexene. The ratio of the radiative and nonradiative transition rates is the luminous efficiency, a macroscopic property parameter characterizing the material.

2. The method for optimizing the DFT calculation model of vibrational-electronic interaction in X-type dihexene configuration as described in claim 1, characterized in that: The specific process of S1 is as follows: This study constructed a dataset of energy barriers, vibrational spectra, electron cloud density, and molecular orbital energy levels for X-type dihexene materials. X-type dihexene crystals with a purity greater than 98% were prepared into a solution, which was then spin-coated into a solid film and grown as single crystals for testing. Energy barrier data acquisition involved selecting an X-type dihexene molecular model, optimizing the initial ground-state configuration using density functional theory (DFT), determining the torsional path of the helical arms and the deformation path of the bond angles at the cross points that affect configuration stability, setting scan variables and step sizes to generate potential energy surface curves, and determining the difference between the transition state energy and the initial state energy from the potential energy surface curves to obtain the energy barrier of the target deformation path. Vibrational spectral data acquisition involved Raman spectroscopy to collect the torsional vibrational peaks of the X-type dihexene solution, smoothing the spectra, and labeling the peak positions, intensities, and full width at half maximum (FWHM) of characteristic peaks. Theoretical vibrational spectra were generated based on DFT calculations, and the experimental peak positions were matched with the theoretical peak positions. Electron cloud density acquisition involved obtaining high-precision electron cloud data through DFT calculations. The B97X-D / def2-TZVP functional basis set outputs wavefunction files and generates electron cloud density surface maps; molecular orbital energy level data is acquired by measuring the photoelectron emission signal of X-type dihexene solid films using ultraviolet photoelectron spectroscopy, calculating the vacuum energy level through the secondary electron cutoff edge, and obtaining the absolute energy level by combining it with the binding energy of the valence band top; and outputting the energy values ​​and wavefunctions of HOMO, LUMO, and nearest neighbor orbitals through DFT calculation.

3. The method for optimizing the DFT calculation model of vibrational-electronic interaction in X-type dihexene configuration as described in claim 1, characterized in that: The definition of the configurational stability of X-type dihexene is as follows: Energy barriers and vibrational characteristics were calculated using vibrational spectra and electron cloud density data. A highly stable X-type dihexene configuration was identified if the energy barrier was >20 kJ / mol, the vibration had no imaginary frequencies, and the torsional frequency was >100 cm⁻¹. A moderately stable configuration was identified if the energy barrier was >20 kJ / mol or the vibration had no imaginary frequencies and the torsional frequency was >100 cm⁻¹. An unstable configuration was identified if the energy barrier was not >20 kJ / mol, the vibration had no imaginary frequencies, and the torsional frequency was not >100 cm⁻¹.

4. The method for optimizing the DFT calculation model of vibrational-electron interaction in X-type dihexene configuration as described in claim 1, characterized in that: The S2 method performs band structure prediction analysis for X-type dihexenes, specifically: based on molecular orbital energy level data, it outputs the initial band distribution; it defines the judgment conditions for low-precision, medium-precision, and high-precision layers of the mixed precision calculation framework and proposes corresponding band gap calculation methods; the band structure consists of the band diagram, band gap value, and the contribution ratio of molecular orbitals to the band, with HOMO contribution ≥ 60% up to the valence band top.

5. The method for optimizing the DFT calculation model of vibrational-electronic interaction in X-type dihexene configuration as described in claim 1, characterized in that: The nonradiative transition analysis of X-type dihexenes using S2 specifically involves: calculating the electronic state energy difference, transition dipole moment, orbital distribution, and equilibrium geometry between excited and ground states using time-dependent density functional theory (TD-DFT); defining an active vibrational mode as one where the vibrational frequency, atomic motion direction, and HT coupling constant all satisfy the criteria; and calculating the transition rate of the active mode based on the vibration-electron coupling strength and the Fermi golden rule.

6. The method for optimizing the DFT calculation model of vibrational-electronic interaction in X-type dihexene configuration as described in claim 1, characterized in that: The specific process of S3 includes: S31, extraction of atomic-scale microstructure information; using the energy barrier, vibrational spectrum, electron cloud density, and molecular orbital energy level data of X-type dihexene collected by S1 as a standardized set of micro parameters; S32, cross-scale correlation algorithm modeling; combined vibration-electronic coupling quantization model and charge-band mapping model, to calculate the mesoscopic properties of X-type dihexene; (1) Vibration-electronic coupling quantification model: based on the lowest excited state of X-type dihexene and ground state The overlap integral of the vibration wave function is the FC factor, with express: ; Must meet ; Using Herzberg-Taylor HT coupling constant Describe the effect of the a-th vibrational mode on electronic transitions. ; In the formula These are the canonical coordinates of vibration mode a. It is a reduction of quality. It is the angular frequency of vibration. It is the Hamiltonian; the HT coupling constant. Must meet ; The weighting ratio of the coupling weight in the spiral torsion mode is ≥40%, and the ratio of the C=C scaling mode is ≥30%. (2) Charge-band mapping model: the electron cloud density at the atomic scale The initial boundary conditions used for mesoscopic calculations satisfy the Poisson equation, expressed as follows: ; In the formula Represents electrostatic potential, Represents the vacuum permittivity. ; to electrostatic potential The periodic DFT calculation using VASP software was introduced to correct the lattice potential function, so that the deviation between the mesoscopic valence band top VBM and the atomic-scale HOMO energy level is <0.2 eV, and the deviation between the conduction band bottom CBM and the LUMO energy level is <0.2 eV. S33, Derivation of macroscopic photoelectric properties; Based on mesoscopic property data, the macroscopic performance parameter luminous efficiency is output through the carrier mobility formula and the luminous efficiency formula. Radiative transition rate, in This indicates that the following calculation expression is satisfied: ; in Let be Planck's constant. For the transition frequency, For the transition dipole moment, Denotes the reduced Planck constant. Represents the speed of light in a vacuum. ; Nonradiative transition rate Represented as: ; In the formula Let ∑ denote the reduced Planck constant. This represents the summation over all strongly coupled active vibrational modes. This represents the square of the HT coupling constant. Represents the FC factor. exist The vibrational dynamic density at a given location is obtained by accumulating the energy distribution of the S0 state vibrational modes. This indicates the temperature-dependent Boltzmann factor; Luminous efficiency Satisfy the following expression: ; In the formula Indicates the radiative transition rate. This represents the nonradiative transition rate.

7. The method for optimizing the DFT calculation model of vibrational-electron interaction in an X-type dihexene configuration as described in claim 1 or 4, characterized in that: The aforementioned prediction and analysis of the X-type dihexene band structure specifically includes the following process: Based on the collected molecular orbital energy level data, including molecular orbital energy levels and wave functions, HOMO and LUMO energies and nearest neighbor orbital distributions; The criteria for determining the low-precision, medium-precision, and high-precision layers of the mixed-precision computation framework are defined as follows: The low-precision layer must satisfy a helical cross angle θ = 60°~90° and a HOMO-LUMO energy level difference E_g^mol = 2.5~3.5 eV; the medium-precision layer must satisfy a π-π stacking distance d = 3.3~3.8 Å and an intermolecular coupling energy V = 0.01~0.1 eV; the high-precision layer must satisfy a band diagram showing a continuous energy-wave vector relationship and having a clearly defined valence band top and conduction band bottom. A bandgap calculation method is defined for a mixed-precision computing framework: the low-precision layer is constructed using the GFN2-xTB semi-empirical method to create a 2×2×1 periodic supercell; The medium-precision layer uses the PBE0-D3 / def2-SVP DFT method to optimize the supercellular molecular configuration and map the single-molecule HOMO / LUMO energy levels to aggregated state orbitals; the high-precision layer uses the GW method to correct the valence band top and conduction band bottom energies.

8. The method for optimizing the DFT calculation model of vibrational-electronic interaction in X-type dihexene configuration as described in claim 5, characterized in that: The defined vibrational frequency, atomic motion direction, and HT coupling constant all satisfy the judgment condition for an active vibrational mode, specifically: Vibration frequency satisfy: ; In the formula, h represents Planck's constant, and n represents a constant with a range of [1,3]. Direction of atomic motion and → The geometric configurations are consistent; The lowest excited state based on X-type dihexene and ground state The overlap integral of the vibration wave function is the FC factor, with express: ; Must meet ; The coupling constant is represented by Herzberg-Taylor (HT). Describe the effect of the a-th vibrational mode on electronic transitions: ; In the formula These are the canonical coordinates of vibration mode a. It is a reduction of quality. It is the angular frequency of vibration. It is the Hamiltonian; HT coupling constant. Must meet .

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