113 results about "Powder diffraction" patented technology

This invention provides a method for preparing and testing powder diffraction standards for determining internal residual stress, belonging to the field of residual stress detection. The powder standards prepared by this invention possess shape retention capabilities, meeting the requirements of the transmission diffraction optical path in non-destructive diffraction determination of internal residual stress. The powder, after being bonded with an adhesive, forms a blocky solid form, and standards of different sizes can be prepared according to the penetration depth of different diffraction sources on different substrate materials. Furthermore, the ratio of powder to adhesive can be adjusted to obtain different diffraction volume ratios. By testing the uniformity of diffraction peak intensity distribution in translational and rotational degrees of freedom, the uniformity of the internal lattice distribution and orientation of the standard sample can be determined, thereby testing and judging the uniformity of the standard sample.

A process for preparing (R)-N-((S)-1-(4-(3,3-dimethyl-2-oxoindolin-1-yl)piperidin-1-yl)-1-oxo-4-phenylbutan-2-yl)piperidine-3-carboxamide HCl-salt Crystalline Form A, wherein the HCl-salt Crystalline Form A is characterized by an X-ray powder diffraction (XRPD) pattern obtained by irradiation with copper K-alpha (Cu Kα) radiation comprising peaks at 14.7±0.2 and 17.5±0.2 degrees two-theta, which comprises the step of crystallizing the crystalline form from a solvent.

The present invention relates to the crystalline form of bipyrimidine compounds, as well as methods for preparing the same and their use. In particular, the present invention relates to crystalline form I of 4'-cyclopropyl-5,6'-dimethoxy-N-((4-(1-methyl-4-(trifluoromethyl)-1H-imidazole-2-yl)bicyclo[2.2.2]octan-1-yl)methyl)-[2,5'-bipyrimidine]-4-amine, wherein the X-ray powder diffraction pattern of crystalline form I includes characteristic peaks at diffraction angles (2θ) of 6.378±0.2°, 9.521±0.2°, 15.721±0.2°, 16.379±0.2°, 16.981±0.2°, 17.560±0.2°, 19.080±0.2° and 22.200±0.2°. Crystal form I possesses high stability, high solubility, high plasma concentration, high bioavailability, and excellent pharmacological activity, making it suitable for pharmaceutical preparations.

Provided are a computing device, a computing method, a program, and a machine learning model generation method for inferring a lattice volume from a distribution pattern of X-ray powder diffraction. A computing device (100) for inferring a lattice volume from a distribution pattern of X-ray powder diffraction includes an information acquisition unit (110) that acquires information related to the distribution pattern of X-ray powder diffraction, and an inference unit (120) that includes a machine learning model that takes information related to the distribution pattern of X-ray powder diffraction as input and outputs an inferred lattice volume, and infers the lattice volume from the information related to the distribution pattern of X-ray powder diffraction acquired by the information acquisition unit (110).

The invention discloses a crystal form of carboxamide triazole. The crystal form I shows characteristic peaks at the positions of 20.3 degrees + / -0.2 degrees, 22.1 degrees + / -0.2 degrees, 23.4 degrees + / -0.2 degrees, 25.2 degrees + / -0.2 degrees, 28.6 degrees + / -0.2 degrees and 28.9 degrees + / -0.2 degrees in an X-ray powder diffraction pattern expressed by a 2theta diffraction angle; the crystal form II shows characteristic peaks at the positions of 3.8 degrees + / -0.2 degrees, 14.9 degrees + / -0.2 degrees, 19.2 degrees + / -0.2 degrees, 22.3 degrees + / -0.2 degrees, 25.4 degrees + / -0.2 degrees and 28.9 degrees + / -0.2 degrees in an X-ray powder diffraction pattern represented by a 2theta diffraction angle; the crystal form III shows characteristic peaks at the positions of 3.4 degrees + / -0.2 degrees, 3.7 degrees + / -0.2 degrees, 12.1 degrees + / -0.2 degrees, 14.8 degrees + / -0.2 degrees, 20.2 degrees + / -0.2 degrees and 24.3 degrees + / -0.2 degrees in an X-ray powder diffraction pattern expressed by a 2theta diffraction angle.

The application discloses an organic amine modified HMS molecular sieve and application thereof in carbon dioxide capture, and specifically relates to the following steps: first, preparing mesoporous molecular sieve HMS, which contains two kinds of pore structures, 4.5-8.0 nm and 11.5-17.5 nm respectively, and a single wide diffraction peak is presented at 2theta=2.6 degrees in X-ray powder diffraction; then, grafting amino silane on the surface of the mesoporous molecular sieve HMS; and finally, immersing the mesoporous molecular sieve HMS in an organic amine solution to obtain a multilevel organic amine modified HMS molecular sieve. The synthesis method is simple, the carbon dioxide adsorption efficiency is high, and the thermal stability is good.

The invention discloses a Bexagliflozin and vitamin C eutectic crystal form and a preparation method and application thereof. An X-ray powder diffraction pattern of a Bexagliflozin and vitamin C eutectic crystal under Cu-Ka radiation comprises peaks at the following 2 theta values: 10.5 + / -0.2 degrees, 10.8 + / -0.2 degrees, 11.1 + / -0.2 degrees, 11.9 + / -0.2 degrees, 12.8 + / -0.2 degrees, 15.5 + / -0.2 degrees, 16.0 + / -0.2 degrees, 16.2 + / -0.2 degrees, 17.4 + / -0.2 degrees, 18.7 + / -0.2 degrees, 19.1 + / -0.2 degrees, 19.8 + / -0.2 degrees, 20.7 + / -0.2 degrees, 21.2 + / -0.2 degrees, 22.4 + / -0.2 degrees, 22.8 + / -0.2 degrees, 23.3 + / - 21.8 + / -0.2 degrees, 22.4 + / -0.2 degrees, 22.7 + / -0.2 degrees, 23.5 + / -0.2 degrees, 24.4 + / -0.2 degrees, 24.7 + / -0.2 degrees, 24.9 + / -0.2 degrees, 25.3 + / -0.2 degrees, 25.8 + / -0.2 degrees, 26.7 + / -0.2 degrees, 27.2 + / -0.2 degrees, 27.5 + / -0.2 degrees, 28.0 + / -0.2 degrees, 29.5 + / -0.2 degrees, 30.0 + / -0.2 degrees, 30.1 + / -0.2 degrees, 30.9 + / -0.2 degrees, 31.4 + / -0.2 degrees and 31.7 + / -0.2 degrees.

The invention belongs to the technical field of lithium ion battery materials, and particularly relates to a crystal form of a lithium ion battery additive ethylene disulfate and a preparation method of the crystal form. An X-ray powder diffraction pattern of the crystal form A comprises 2theta values of 21.0 + / -0.2 degrees, 23.8 + / -0.2 degrees and 24.6 + / -0.2 degrees; an X-ray powder diffraction pattern of the crystal form B contains 2 theta values of 12.2 + / -0.2 degrees, 18.0 + / -0.2 degrees, 24.4 + / -0.2 degrees and 36.9 + / -0.2 degrees. The crystal form provided by the invention is large in particle size, easy to remove water, capable of obtaining a product with low water content, high in stability, controllable in crystal form, low in requirements on storage conditions and capable of being stably stored, and the transportation cost and the production cost are saved; and the battery capacity retention rate and the battery capacity recovery rate can be improved, the capacity fading of the battery is delayed, the internal resistance of the battery is reduced, and a better interface composition adjusting effect is achieved.

A processing device (400) for performing non-negative matrix factorization on measured X-ray powder diffraction profiles comprises a measurement profile acquisition section (410) for acquiring a plurality of measured profiles, a decomposition section (420) for applying non-negative matrix factorization to the measured profiles and for calculating base profiles; an index calculation section (430) for acquiring the base profiles and for calculating indices based on a non-uniformity of the base profiles; a base profile classification section (440) for classifying the base profiles into a plurality of groups based on the indices; and a base profile correction section (450) for performing a correction based on the indices on at least one of the plurality of groups and for calculating a corrected base profile.

The invention belongs to the technical field of crystal engineering, and discloses a lutein-glutamic acid eutectic crystal and a preparation method and application thereof, Cu-k alpha radiation is used, and the lutein-glutamic acid eutectic crystal has characteristic peaks at 21.75 + / -0.2 degrees, 25.95 + / -0.2 degrees, 31.34 + / -0.2 degrees and 35.96 + / -0.2 degrees in an X-ray powder diffraction pattern represented by a diffraction angle 2 theta. According to the lutein-glutamic acid eutectic crystal provided by the invention, on the premise of not changing the pharmacological activity of the lutein, the solubility and the dissolution rate of the lutein are remarkably improved, and the stability of the lutein-glutamic acid eutectic crystal under the conditions of high temperature, high humidity and strong light is greatly enhanced; in-vitro cell experiments further prove that compared with pure xanthophyll, the xanthophyll-glutamic acid eutectic has more excellent cell aging resistance, oxidation resistance and vasodilation promoting activity, and an ideal dosage form is provided for efficient application of xanthophyll in medicines and functional foods.

The invention belongs to the technical field of medicines, and particularly relates to a crystal form IV of an sGC agonist as well as a preparation method and application of the crystal form IV. The crystal form IV of the sGC agonist is the crystal form IV of a compound I. The crystal form IV has diffraction peaks at the positions of 9.2951 degrees, 17.9978 degrees, 18.5726 degrees, 19.7368 degrees, 21.6855 degrees and 25.2649 degrees in an X-ray powder diffraction spectrum represented by a diffraction angle of 2 theta + / -0.2 degrees. The crystal form IV of the sGC agonist LXH-1211 provided by the invention provides a technical guarantee for subsequent research and development of drugs and maintenance of consistency of pharmacokinetic and pharmacokinetic properties of the drugs, and also can provide a technical support for subsequent industrial production of drugs with specific crystal forms.

The invention provides a crystal form of an edoxaban intermediate and a preparation method thereof, and relates to the field of medicinal chemistry. The structural formula of the edoxaban intermediate is as shown in formula I; the crystal form of the edoxaban intermediate comprises a crystal form A, a crystal form B or a mixture of the crystal form A and the crystal form B in any proportion. The X-ray powder diffraction pattern of the crystal form A of the edoxaban intermediate has characteristic absorption peaks at the positions of 2theta angles of 11.20 degrees, 17.66 degrees, 18.61 degrees, 19.29 degrees and 27.40 degrees; the X-ray powder diffraction pattern of the crystal form B of the edoxaban intermediate has characteristic absorption peaks at the positions of 2 theta angles of 7.99 degrees, 10.82 degrees, 13.33 degrees, 18.22 degrees, 18.48 degrees, 19.34 degrees and 20.02 degrees. The stable crystal form of the compound shown in the formula I can be successfully obtained, the crystal form of the compound shown in the formula I can be directly used as an intermediate to be stored and used, and the synthesis route of edoxaban is simplified.

Provided are a crystal form of a five-membered and six-membered compound, a preparation method and application thereof, in particular, a crystal form A, a crystal form B, a crystal form C, a crystal form D, a crystal form F, a crystal form G, a crystal form H, a crystal form I or a crystal form J of a five-membered and six-membered compound as shown in formula X. The crystal form A has an X-ray powder diffraction pattern expressed by a 2θ angle using Cu-Kα radiation, and has diffraction peaks at 6.9±0.2°, 11.2±0.2°, 12.2±0.2°, 13.7±0.2°, 17.3±0.2°, 18.2±0.2° and 24.3±0.2°. The crystal form of the five-membered and six-membered compound provided has an inhibitory or / and degrading effect on IRAK4, has potential clinical application value, is expected to improve the prognosis of patients and reduce the possibility of drug resistance, and has good solubility, physical and chemical stability and mechanical stability.

The invention discloses a beta crystal form of arfamarin as well as a preparation method and application thereof, and relates to the technical field of anthelmintics for dogs, the crystal form is a hydrate crystal form, and the molecular formula is C26H19ClF9N3O4; the X-ray powder diffraction pattern of the crystal form is shown as follows: 2theta = 5.38 degrees, 8.10 degrees, 9.79 degrees, 12.43 degrees, 13.71 degrees, 13.91 degrees, 14.86 degrees, 15.15 degrees, 15.56 degrees, 16.26 degrees, 16.84 degrees, 17.38 degrees, 17.71 degrees, 18.33 degrees, 18.78 degrees, 19.64 degrees, 19.93 degrees, 20.68 degrees, 21.54 degrees, 22.16 degrees, 22.49 degrees, 23.68 degrees, 24.14 degrees, 24.67 degrees, 25.05 degrees, 25.50 degrees, 26.53 degrees, 27.27 degrees, 28.01 degrees, 29.21 degrees, 29.79 degrees, 30.16 degrees, 31.35 degrees, 31.89 degrees, 32.75 degrees, 33.33 degrees The infrared spectrum of the crystal form at least has characteristic peaks at 3360 cm <-1 >, 3070 cm <-1 >, 1705 cm <-1 >, 1641 cm <-1 >, 1534 cm <-1 >, 1327 cm <-1 >, 1170 cm <-1 > and 829 cm <-1 >. A differential scanning calorimetry (DSC) curve of the crystal form shows that a desolventizing endothermic peak exists in an interval of 61.0 DEG C to 102.4 DEG C.

This invention belongs to the field of pharmaceutical chemistry technology, specifically relating to a monopravir-caprolactam cocrystal, its preparation method, and its applications. The monopravir-caprolactam cocrystal is composed of monopravir and caprolactam in a molar ratio of 1:1.9-2.1. X-ray powder diffraction was performed using Cu-Kα radiation, with angles expressed as 2θ±1, at 6.91, 7.09, 8.38, 11.24, 12.52, 13.26, 13.87, 14.24, 15.22, 16.82, 17.31, and 1... Characteristic peaks are observed at 9.73, 20.22, 20.53, 20.84, 21.90, 22.28, 22.52, 22.95, 23.51, 23.75, 24.00, 24.31, 24.86, 25.35, 26.44, 27.41, 28.02, 28.69, 29.22, 29.84, and 30.33. Monopravir-caprolactam cocrystals can be successfully prepared by grinding and / or solution methods, and grinding and / or melting methods. The preparation process is simple, and the obtained product has high purity. Characterization has confirmed it to be a new cocrystal. Powder flowability and tableting tests revealed that the monopravir-caprolactam cocrystals provided by this invention have better flowability and tableting properties compared to monopravir crystal form I, meeting the requirements of formulation and manufacturing processes.

This positive electrode mixture contains a carbon material, a sulfur-based active material, and an ion conductor containing lithium atoms, phosphorus atoms and halogen atoms, and has diffraction peaks at 2θ = 29.3 ± 0.5° and 2θ = 34.0 ± 0.5° according to X-ray powder diffraction using CuKα radiation.

The invention belongs to the technical field of medicines, and particularly relates to a crystal form XVI of an sGC agonist as well as a preparation method and application of the crystal form XVI. The crystal form XVI of the sGC agonist is the crystal form XVI of a compound I. The crystal form XVI has diffraction peaks at the positions of 9.7733 degrees, 10.5581 degrees, 15.6149 degrees, 16.4871 degrees, 18.6864 degrees, 19.121 degrees, 19.5957 degrees, 20.9453 degrees, 21.878 degrees, 22.2877 degrees, 24.2135 degrees, 24.6459 degrees, 26.522 degrees and 28.023 degrees in an X-ray powder diffraction pattern represented by a diffraction angle of 2 theta + / -0.2 degrees. Technical guarantee is provided for subsequent research and development of drugs and maintenance of consistency of pharmacokinetic and pharmacokinetic properties of the drugs, and meanwhile, technical support can be provided for subsequent industrial production of drugs with specific crystal forms.

The invention relates to a preparation method of an omariglitazone dispersion and a quantitative crystal form detection method of the omariglitazone dispersion. The preparation method comprises the following steps: dissolving crystalline omarigliflozin hemicalcium salt (bulk drug) and a dispersing agent in an alcohol solvent according to a ratio, and preparing the dispersion by adopting a spray drying mode. The detection method comprises the following steps: performing X-ray powder diffraction on a reference substance, and measuring the peak area of the reference substance; measuring the peak area of a test sample (omarignelone dispersion): performing X-ray powder diffraction on the test sample, and measuring the peak area of the test sample; comparing the peak area of the test sample with the peak area of the reference substance, and calculating the crystallinity of the omariglitazone hemicalcium salt in the test sample according to a formula. According to the preparation method of the omariglitazone dispersoid, the inclusion effect is good, and the prepared dispersoid does not contain crystalline omariglitazone hemicalcium salt. The detection method established by the invention is high in sensitivity, good in stability and short in detection time, meets qualitative and quantitative detection requirements, and effectively improves the detection efficiency.

The invention belongs to the technical field of medicines, and particularly relates to a crystal form XXI of an sGC agonist as well as a preparation method and application of the crystal form XXI. The crystal form XXI has diffraction peaks at the positions of 9.1247 degrees, 9.4385 degrees, 15.2708 degrees, 16.1429 degrees, 17.3222 degrees, 17.6586 degrees, 18.3906 degrees, 18.734 degrees, 19.217 degrees, 20.0426 degrees, 20.8807 degrees, 21.3881 degrees, 23.1609 degrees, 23.5369 degrees, 24.106 degrees, 24.5057 degrees, 26.0111 degrees and 26.2379 degrees in an X-ray powder diffraction pattern represented by a diffraction angle of 2 theta + / -0.2 degrees. Technical guarantee is provided for research and development of subsequent drugs and maintenance of consistency of pharmacokinetic and pharmacokinetic properties of the drugs.

Provided herein are integrin inhibitors, compositions thereof, and methods of their uses. Crystalline forms of salts of the inhibitors are also described, along with methods of preparing the crystalline forms. X-ray powder diffraction data, thermogravimetric analysis, and differential scanning calorimetry data are provided for the crystalline forms. The integrin inhibitors are useful for treatment of, inter alia, fibrotic diseases.

The present invention provides a crystalline form Form I of a pyrazolopyrimidine ester compound of the structure of formula (I)This crystalline form has been characterized using X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The present invention also provides methods of preparing the crystalline form Form I of the pyrazolopyrimidine ester compound. This crystalline form allows long-term storage without special requirements in respect of temperature, light, humidity or oxygen presence and is significantly advantageous in terms of stability. Moreover, the methods involve simple steps and provide good reproducibility and excellent purity. Therefore, they have a promising prospect of extensive application.

The invention discloses an upatinib eutectic crystal form as well as a preparation method and application thereof, and belongs to the technical field of medicinal chemistry. The invention provides an eutectic crystal form I formed by upatinib and vanillic acid and an eutectic crystal form G formed by upatinib and syringic acid, which have definite and reproducible characteristic X-ray powder diffraction pattern and melting point, have excellent solubility in an aqueous medium, do not generate crystal form transformation after being stored for 1 month under the condition of relative humidity of 40 DEG C / 75%, and can be used for preparing a crystal form of upatinib. And the stability is good. The preparation process route is short, the operation condition is mild, the used solvent is conventional, the target eutectic can be efficiently and repeatedly obtained, the defects that some existing eutectic preparation processes are complex, long in period or harsh in condition are overcome, and the method has good process amplification and industrialization prospects.

The invention belongs to the technical field of medicines, and particularly relates to a crystal form VIII of an sGC agonist as well as a preparation method and application of the crystal form VIII. The crystal form VIII of the sGC agonist is the crystal form VIII of the compound I. The X-ray powder diffraction pattern of the crystal form VIII, which is represented by a diffraction angle of 2 theta + / -0.2 degrees, has diffraction peaks at the positions of 8.8902 degrees, 9.818 degrees, 15.9516 degrees, 16.5412 degrees, 17.851 degrees, 19.5499 degrees, 20.0096 degrees, 21.4687 degrees, 24.3685 degrees and 25.3691 degrees. The crystal form VIII of the sGC agonist LXH-1211 provided by the invention provides a technical guarantee for subsequent research and development of drugs and maintenance of consistency of pharmacokinetic and pharmacokinetic properties of the drugs, and also can provide a technical support for subsequent industrial production of drugs with specific crystal forms.

[Problem] To provide an atorvastatin calcium anhydride crystal having higher solubility than that of a conventional hydrate crystal and being more stable than an amorphous form. [Solution] The present invention pertains to an atorvastatin calcium anhydride crystal that exhibits an X-ray diffraction pattern, which has peaks at 2θ = 8.7°, 10.4°, 18.1°, 19.5°, 20.9°, 22.5°, 24.1°, and 25.6°, by X-ray powder diffraction measurement (XRPD) using CuKα radiation.

The invention relates to a crystal form of NADH (nicotinamide adenine dinucleotide) disodium salt and a preparation method of the crystal form. The crystal form I is radiated by CuK alpha, and diffraction peaks at least exist at the positions of 12.845 degrees + / -0.2 degrees, 18.379 degrees + / -0.2 degrees, 20.240 degrees + / -0.2 degrees, 21.998 degrees + / -0.2 degrees and 23.536 degrees + / -0.2 degrees in an X-ray powder diffraction spectrum expressed by a 2 theta angle. The crystal form I has the advantages of good stability, good moisture absorption resistance, simple preparation method and the like, and is suitable for large-scale production.

Disclosed herein are solid forms containing a compound of formula (I):a solvate, hydrate or isotope thereof, wherein the solid form is characterized by an X-ray powder diffraction pattern having at least one peak position, in degrees 2θ (±0.2°), selected from 5.48, 13.74, 19.22 and 20.06. Also disclosed herein are related pharmaceutical compositions and methods of treatment.

This disclosure provides a sample holder, diffraction testing system, and method for X-ray powder diffraction. The sample holder includes: a clamping part capable of clamping onto an XYZ triaxial base and being positionally adjusted along the XYZ axes by the base; the clamping part includes a hollow cylindrical portion and a hollow frustum portion located above the hollow cylindrical portion, the hollow cylindrical portion and the hollow frustum portion being coaxial and having the same inner diameter; a loading part including a first cylindrical portion and an annular portion located above the first cylindrical portion, the annular portion having holes for filling the sample, and the first cylindrical portion being insertable into the hollow frustum portion from above; and a pressing needle part including a second cylindrical portion for holding and a third cylindrical portion for filling and compacting the sample into the loading part. The X-ray powder diffraction sample holder of this disclosure can effectively fix experimental samples for X-ray powder diffraction.

The invention discloses a method for preparing a niflufenamic acid crystal form through melt crystallization, and relates to a preparation method of a medicine crystal form. The crystal form A prepared by the invention has characteristic peaks at 9.8 + / -0.2 degrees, 12.6 + / -0.2 degrees, 16.7 + / -0.2 degrees, 23.4 + / -0.2 degrees and 25.6 + / -0.2 degrees according to X-ray powder diffraction 2 theta. The crystal form A is good in thermal stability, the quality is basically kept stable below 200 DEG C, and the crystal form A can stably exist for more than four weeks under the condition of 40 DEG C / 75% RH; meanwhile, the hygroscopicity is low, the transportation and long-term storage of the product are facilitated, the solubility is good, the solubility in an ethanol solution at 25 DEG C for 24 hours can reach about 0.013455 mg / mL, and the absorption of the medicine in a human body can be promoted. The crystal form of niflufenamic acid (NFA) is a non-steroidal anti-inflammatory drug and has pharmacological activities of resisting inflammation, easing pain and relieving fever.

A solid alumina composition is prepared from an acid-treated precursor composition, the precursor composition having an alumina hydroxide (Al(OH)3), aluminum oxyhydroxide (AlO(OH)), or a mixture thereof; where the solid alumina composition includes η-alumina characterized by having an X-ray powder diffraction pattern with peaks at 19.6±0.5° 2θ and 66.8±0.5° 2θ; and where the solid alumina composition has an acidity measured by an NH3-TPD test, characterized by: (1) an acid site density ranging from about 200 to 800 μmol / g; and / or (2) an acid strength distribution of: about 20%-70% weak acid sites (such as about 30-50%, about 30-40%, or about 35-40%), about 30%-80% medium acid sites (such as about 50-70%, about 60-70%, or about 60-65%), and about 0-20% strong acid sites (such as about 0-10%, about 0-5%, or about 0-2%).

This invention discloses a selenite crystal and its preparation method. X-ray powder diffraction of the selenite crystal, measured using Cu-Kα radiation, yielded diffraction angles (expressed as 2θ) of 17.7°±0.2°, 19.5°±0.2°, 20.0°±0.2°, 22.9°±0.2°, 24.5°±0.2°, 24.9°±0.2°, 26.2°±0.2°, 29.8°±0.2°, 30.2°±0.2°, 31.4°±0.2°, and 33°. Characteristic peaks are observed at 0°±0.2°, 34.3°±0.2°, 35.8°±0.2°, 36.6°±0.2°, 37.4°±0.2°, 37.5°±0.2°, and 38.4°±0.2°. A characteristic endothermic peak is observed at 73.4℃ in the differential scanning calorimetry (DSC) spectrum of the crystal. This invention features a simple preparation route, mild reaction conditions, convenient operation, low cost, and good process reproducibility. The prepared selenite has a stable crystal form, making it suitable for large-scale industrial production of pharmaceutical raw materials.