基态B_n(n=2,3)结构与完全解析势能函数  

Structure and analytic potential energy functions for ground state of B_n(n=2,3)molecular

作　　者：祝恒江[1] 路俊哲[1] 魏婕[1] 刘立仁[1] 

机构地区：[1]新疆师范大学物理与电子工程学院,乌鲁木齐830054

出　　处：《原子与分子物理学报》2014年第1期6-14,共9页Journal of Atomic and Molecular Physics

基　　金：新疆维吾尔自治区自然科学基金(2010211a21);新疆维吾尔自治区高校科研计划重点项目(XJED U2009127);新疆师范大学优秀青年教师科研启动基金(XJNU1215);新疆师范大学理论物理自治区重点学科招标课题(13XSQZ0601);新疆师范大学研究生创新基金(20121216);理论物理自治区重点学科研究生创新基金(LLWLY201104)

摘　　要：使用Gaussian03程序包,采用全电子单双取代耦合簇(CCSD(full))方法,选择基组6-311+g(2df),对B2分子的基态进行优化计算,采用十一参量Murrell-Sorbie函数,运用最小二乘法拟合得到B2分子基态解析势能函数,给出与实验值符合很好的光谱常数;使用同样的方法和基组,对B3分子的基态结构进行优化计算,得到B3分子基态平衡结构.采用多体项展式法,利用B3分子平衡结构C2v的几何参数、力常数和离解能,以及七个线性系数Ci(i=1,2,3,4,5,6,7)与两个非线性系数的函数关系,进行非线性优化拟合得到两个非线性系数,进而得到七个线性系数,得到B3分子基态完全解析势能函数.势能面静态特征表明,该势能函数准确再现了B3分子基态全部平衡结构特征.The molecular structures of ground state of B2 are calculated on the level of 6-311＋g （2d f） basis set using CCSD（full） method in Gaussian03 programs. Its potential energy functions have been derived by the least-square fitting method and the eleven-parameter Murrell-Sorbie function, and the obtained spectroscopic constants are in good agreement with the experimental values; The ground state structures of Ba have been optimized by the same method and basis set. By using the Ba molecular＇s balance structure C2v geometric parameters, the force constant, dissociation energy and the function relations of the linear and nonlinear coefficients, and in terms of a nonlinear optimization fitting made in the near minimum point of B3 molecular potential energy surface, the nonlinear coefficients and then the linear coefficients Ci（i=1, 2, 3, 4, 5, 6, 7） are obtained. With the many-body expansion, the completely analytical potential energy functions of ground state of the B3 molecular are also derived. The ground state equilibrium geometries of B3 are reproduced by the completely potential energy functions and shown in the potential energy surfaces exactly.

关 键 词：B2 B3 完全解析势能函数 多体项展式法 

分 类 号：O561.1[理学—原子与分子物理]