用耦合簇方法及相关一致基研究PH_2(X^2B_1)自由基的解析势能函数  

Analytic potential energy function of PH_2(X^2B_1)radical using coupled-cluster method in combination with the correlation-consistent basis sets

作　　者：张东玲[1] 汤清彬[1] 张金平[1] 施德恒[1] 余本海[1] 

机构地区：[1]信阳师范学院物理电子工程学院,信阳464000

出　　处：《物理学报》2009年第8期5323-5328,共6页Acta Physica Sinica

基　　金：河南省高校科技创新人才支持计划(批准号:2008HASTIT008)资助的课题~~

摘　　要：利用耦合簇方法和Dunning等提出的系列相关一致基对PH2自由基的基态结构进行优化,并使用优选出的cc-pV5Z基组对其进行频率计算.结果表明,平衡核间距RP—H=0.14185nm,键角αHPH=91.8624°,离解能De(HP—H)=3.483eV,对称伸缩振动频率ν1(a1)=2399.9781cm-1,弯曲振动频率ν2(a1)=1128.4213cm-1,反对称伸缩振动频率ν3(b2)=2407.8374cm-1.在此基础上采用多体项展式理论导出了PH2自由基的解析势能函数,其等值势能图准确再现了PH2自由基分子的平衡结构特征和动力学特征.The equilibrium geometries for the ground state of PH2 radical are calculated by using the coupled-cluster single-double model with a perturbative triple excitations （CCSD（T）） method in combination with the series of correlation-consistent basis sets of Dunning and co-workers. It can be found that the cc-pV5Z basis set is the most suitable basis set by comparing the calculations with the experiment. The results obtained at CCSD（T）/ cc-pV5Z level of theory are 0. 14185 nm for the equilibrium bond length RP-H, 91.8624° for the bond angle αHPH, 3.483 eV for the dissociation energy D1 and 2399.9781, 1128.4213 and 2407. 8374 cm- 1 for the normal of vibrational frequencies V1 （ a1 ）, u2 （ a1 ） and v3 （ bE ）, respectively, The potential energy function of PHz （ C2v, X2 B1） is derived using many-body expansion theory. The characters of structure and the change of energy are reflected correctly by the function

关 键 词：PH2自由基 多体项展式理论 解析势能函数 

分 类 号：O561.1[理学—原子与分子物理] O621.12[理学—物理]