Study on the Near-Infrared Spectra of Sarin Based on Density Functional Theory

vibration mode of the molecule. The generalized second-order perturbation theory ( GVPT2) is introduced to establish a theoretical model for simulating the near-infrared spectrum of biochemical poisons, obtaining the near-infrared vibration peaks and main vibration modes, and the near-infrared spectrum drawn from the vibrations of overtones and combination bands. Analyze the hydrogen-containing groups of sarin in the near-infrared region, use this method to identify its characteristic peaks, obtain three characteristic peaks of sarin molecules at 1 150, 1 362 and 1 500 nm and analyze their vibration modes. Among them, the position at 1 150 nm is produced by the contribution of multiple overtones and combination bands vibration. 1 362 nm is a wide absorption vibration region, mainly caused by the combination bands of atoms connected to C atoms in the molecule and other non-C, H atoms. The near-infrared vibration peak at 1 500 nm is mainly caused by the CS Related vibration mode contribution. In this paper, the theoretical model of Sarin's near-infrared spectroscopy is established through density functional theory, and the feasibility of the theoretical model is verified through experiments, which provides theoretical support for finding its near-infrared spectroscopy simulation agent.