Accurate ab initio double many-body expansion potential energy surface for ground-state H2S by extrapolation to the complete basis set limit
作者单位：Departamento de Química Universidade de Coimbra
会议名称：《第七届全国青年计算物理学术会议》
会议日期：2013年
学科分类：07[理学] 070202[理学-粒子物理与原子核物理] 0702[理学-物理学]
基 金：the support of Fundao para a Ciência e a Tecnologia Portugal Contract Nos. POCI/QUI/60501/2004and REEQ/128/QUI/2005 under the auspices of POCI 2010 of Quadro Comunitário de Apoio Ⅲ co-financed by FEDER
摘 要：A single-sheeted potential energy surface is reported for the electronic ground-state of H2S by fitting accurate multireference configuration interaction energies calculated using aug-cc-pVTZ and aug-cc-pVQZ basis sets with extrapolation of the electron correlation energy to the complete basis set limit, plus extrapolation to the complete basis set limit of the complete-active-spaceself-consistent field energy. A switching function formalism has been used to warrant the correct behavior at the H2X1g++ S1D and SH X2+ H2S dissociation limits. The topographical features of the novel global potential energy surface are examined in detail, with the former being used for exploratory quasiclassical trajectory calculations of the thermal rate constant for the S1D + H2, S1D + D2, and S1D + HD reactions at room temperature. A comparison with other available potential energy surfaces as well as kinetics data is also provided.