Ne—Na_2分子基态势能面的从头算及分析拟合

Ab initio Calculation and Analytic Fits on the Potential Energy Surface for Ne—Na_2 Complex

采用aug-cc-p VQZ(弥散函数的基组)/Na、aug-cc-p VDZ(弥散函数的基组)/Ne以及中点键函数的大基组,使用单、双迭代并包含三重激发微扰校正的耦合簇CCSD(T)理论方法,计算了Ne—Na2基态146个基态单点能.通过拟合96个参数,给出了Ne—Na2三原子分子体系的基态分子势能函数的解析表达式,并分析了其基态二维势能面的特性,在此基础上绘出了Ne—Na2三原子分子体系的三维势能曲线.计算结果表明,Ne—Na2基态势能面存在2个较浅的势阱,对应于θ=80°,RNe—Na=3.3a0处,势阱的阱深约为-6.750×10-1cm-1和线型结构θ=0°,RNe—Na=10a0处,势阱深度约为-2.341×10-3cm-1.此三原子分子体系的势能面呈现出弱的角度各向异性.

By using the aug-cc-p VQZ（ Augmented versions of the preceding basis sets with added diffuse functions）/ Na,aug-cc-p VDZ（ Augmented versions of the preceding basis sets with added diffuse functions） / Ne and the bond functions（ bf） basis sets,three-dimensional potential energy surfaces（ PES） for the interaction of rigid Na2 with Ne are calculated. The coupled cluster singles-and-doubles with noniterative inclusion of connected triple [CCSD（ T） ]level of theory are used. The 146 ab initio points on the PES are fitted to a 96-parameter. The results of the interaction energy calculations and the corresponding fits to analytical functions are presented. Contour plots also are given. The deeper potential well is θ = 80°,RNe—Na= 3. 3a0 with well depth- 6. 750 × 10^- 1cm^- 1. The linear configuration with well depth- 2. 341 × 10^- 3cm^- 1is at θ = 0°,RNe—Na= 10a0. The whole potential energy surface exhibits weak anisotropy.