Short range force effects in semiclassical molecular line broadening calculations
Short range force effects in semiclassical molecular line broadening calculations
复制标题
半经典分子谱线展宽计算中的短程力效应
DOI：
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发表时间：
1979
期刊：
影响因子：
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通讯作者：
J. Bonamy
中科院分区：
文献类型：
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作者：
D. Robert;J. Bonamy
本文在碰撞近似下发展了气相中孤立红外线和拉曼线的宽度和位移的半经典理论。由相互作用势的各向同性部分确定的抛物线轨迹模型允许对导致弹性碰撞截面的解析表达式的近距离碰撞进行令人满意的处理。这一理论的数值测试已经取得了HCl-Ar通过比较目前的结果与以前的无限阶处理使用数值曲线的经典轨迹。扩展到硅藻-硅藻碰撞，然后通过表达各向异性势使用原子-原子相互作用模型，考虑到长和短距离的贡献。对纯N_2、CO_2和CO的拉曼谱线宽度以及纯CO和受N_2和CO_2扰动的CO的红外谱线宽度进行了数值计算。一个很好的定量协议与实验得到的所有考虑的情况下，并实现了正确的变化的加宽系数与旋转量子数与以前的结果相反。一个一致的变化的线加宽与温度也得到了即使是高旋转水平。
A semiclassical theory of the width and shift of isolated infrared and Raman lines in the gas phase is developed within the impact approximation. A parabolic trajectory model determined by the isotropic part of the interaction potential allows a satisfactory treatment to be made of the close collisions leading to an analytical expression for the elastic collision cross section. A numerical test of this theory has been made for HCl-Ar by comparing the present results to those of previous infinite order treatments using numerical curved classical trajectories. Extension to the diatom-diatom collisions is then made by expressing the anisotropic potential using an atom-atom interaction model which takes both the long and short range contributions into account. Numerical applications have been performed for the Raman line widths of pure N2, CO2 and CO and for the infrared line widths of pure CO and of CO perturbed by N2 and CO2. A good quantitative agreement with experiments is obtained for all the considered cases and a correct variation of the broadening coefficient with the rotational quantum number is achieved in opposition to the previous results. A consistent variation of the line broadening with temperature is also obtained even for high rotational levels.