基于密度泛函理论的BeS分子基态势能函数与光谱常数研究  

A Study on Potential Energy Function and Spectroscopic Parametters for the Ground State of a BeS Molecule Based on Density Functional Theory

作　　者：熊保库[1] 陈东[1] 施德恒[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：《内蒙古大学学报（自然科学版）》2013年第5期464-469,共6页Journal of Inner Mongolia University：Natural Science Edition

基　　金：国家自然科学基金项目(10574039);河南省教育厅自然科学研究项目(2011B140020)

摘　　要：利用原子分子反应静力学的有关原理,推导出了BeS分子基态的合理离解极限;采用密度泛函理论的B3LYP方法,在相关一致基cc-PVnZ(n=2,3,4,5)及aug-cc-PVnZ(n=2,3,4,5)基组下,对BeS分子基态(X1Σ+)的平衡几何、离解能和谐振频率进行了优化计算,应用优选的B3LYP/aug-cc-PVDZ对BeS分子的基态进行了单点能量扫描,采用最小二乘法拟合Murrell-Sorbie势能函数,并计算了与该态相应的光谱常数(Be,αe,ωe和ωeχe),其结果与实验符合得较好.通过求解核运动的径向薛定谔方程找到了转动量子数J=0时BeS分子基态的全部振动能级和转动惯量.The possible reasonable dissociation limits for BeS at the ground state are determined by using the principle of atomic and molecular reaction statics. The dissociation energy,equilibrium geometry and harmonic frequency of the ground state X were calculated by the B3LYP of density functional theory method at the basis sets of cc--PVnZ（nz2,3,4,5） and aug--cc--PVnZ（nz2,3, 4,5）. After scanning the whole potential curve for the ground state by using B3LYP/aug--cc-- PVDZ, a least square fitting to the Murrell--Sorbie function was obtained. At last, the spectroscopic constants（ B,ae,eZe ） are calculated according to the M--S function,they are in good agree- ment with the experimental data. By solving the radial Schrodinger equation of nuclear motion the vibration levels and inertial rotaion constant at rotational quantum number J = 0 are reported for the ground state.

关 键 词：原子分子物理 势能函数 电子结构 基态 振动能级 

分 类 号：O561.1[理学—原子与分子物理]