Photodissociation dynamics of H2S on new coupled ab initio potential energy surfaces
Photodissociation dynamics of H2S on new coupled ab initio potential energy surfaces
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DOI：
10.1063/1.479214
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发表时间：
1999-08
影响因子：
4.4
通讯作者：
David Simah;B. Hartke;H. Werner
中科院分区：
文献类型：
--
作者：
David Simah;B. Hartke;H. Werner
利用高度相关的CASSCF-MRCI波函数和大基集计算了电子基态的三维势能面以及最低的三个1A″态。在最低两个1A″态的准绝热势能面中，采用近似绝热方案。非绝热波函数的非绝热波函数的轨道和组态系数随几何形状的变化尽可能小，这是非绝热波函数的基本条件。非绝热势能面用于随时间变化的吸收谱模拟以及振动和旋转积分布。计算得到的吸收光谱和产物分布与实验结果吻合较好，表明从头算电位和绝热化方案是准确的。
Three-dimensional potential energy surfaces for the electronic ground state as well as the lowest three 1A″ states have been computed using highly correlated CASSCF-MRCI wave functions and a large basis set. An approximate diabatization scheme has been employed to generate quasidiabatic potential energy surfaces for the lowest two 1A″ states. The diabatization is based on the condition that both the orbitals as well as the configuration coefficients of the diabatic wave functions change as little as possible as function of geometry. The diabatic potential energy surfaces are used in time-dependent simulations of the absorption spectrum as well as the vibrational and rotational product distributions. Excellent agreement between the computed and experimental absorption spectra and product distributions is obtained, indicating that the ab initio potentials as well as the diabatization scheme are accurate.