Calculation of Mechanical Properties, Electronic Structure and Optical Properties of CsPbX3 (X = F, Cl, Br, I).

We utilized a first-principle density functional theory for a comprehensive analysis of CsPbX3 (X = F, Cl, Br, I) to explore its physical and chemical properties, including its mechanical behavior, electronic structure and optical properties. Calculations show that all four materials have good stability, modulus of elasticity, hardness and wear resistance. Additionally, CsPbX3 demonstrates a vertical electron leap and serves as a semiconductor material with direct band gaps of 3.600 eV, 3.111 eV, 2.538 eV and 2.085 eV. In examining its optical properties, we observed that the real and imaginary components of the dielectric function exhibit peaks within the low-energy range. Furthermore, the dielectric function gradually decreases as the photon energy increases. The absorption spectrum reveals that the CsPbX3 material exhibits the highest UV light absorption, and as X changes (with the increase in atomic radius within the halogen group of elements), the light absorption undergoes a red shift, becoming stronger and enhancing light utilization. These properties underscore the material's potential for application in microelectronic and optoelectronic device production. Moreover, they provide a theoretical reference for future investigations into CsPbX3 materials.

[Identification on Xanthium sibiricum from different habitats by FTIR fingerprint patterns].

OBJECTIVE: To establish an FTIR method to identify Xanthium sibiricum from different habitats. METHODS: FTIR spectra of Xanthium sibiricum from different habitats were analyzed,and the similarity of different fingerprint spectra and the chemical pattern recognition were calculated and analyzed according to the wave numbers of peaks. RESULTS: Different FTIR spectra of 10 different habitats of Xanthium sibiricum were obtained,and the similarities were all above 0. 96. CONCLUSION: This method can be used for identification on Xanthium sibiricum from different habitats. The results of similarity calculation and chemical pattern recognition further prove the feasibility of this method.

[Identification on Solanum lyratum by FT-IR fingerprint patterns and similarity degree of different fingerprint patterns].

OBJECTIVE: To provide a FT-IR new method to identify different habitats of Solanum lyratum. METHODS: Analyzed FT-IR patterns of Solanum lyratum from different habitats, and the similarity of different fingerprint patterns was calculated and analyzed according to the wave numbers of peaks searched. RESULTS: Obtained the different FT-IR pattern of 5 different habitats of Solanum lyraturn. CONCLUSION: This method can be used for identifications on different habitats of Solanum lyratum. The results of similarity calculation further prove the feasibility of this method.

[Identification on Solanum lyratum by X-ray diffraction Fourier fingerprint and similarity analysis].

OBJECTIVE: To provide an X-ray diffraction (XRD) method for identifying different medicinal parts of Solanum lyratum. METHODS: Analyzed X-ray diffraction Fourier patterns of different parts of Solanum lyratum, and the similarity degree of different fingerprint was calculated and analyzed according to the position (2 theta value)of peaks searched. RESULTS: Different X-ray diffraction Fourier patterns of different medicinal parts of Solanum lyratum were obtained. CONCLUSION: This method can be used for identifying different medicinal parts of Solanum lyratum. The results of similarity calculation further proves the feasibility of this method.