模型势函数的正则坐标展式确定多原子分子力场的研究

提出了直接在正则坐标下模拟多原子分子力场的方法，在正则坐标下，势能函数的展开式无交叉项，整个模拟过程是以大大简化，用此方法，我们在ａｂ ｉｎｉｔｉｏ水平上获得了多原子分子的力常数，将其用于分子振动分析计算，所得结果优于从头算梯度法等其它理论方法的结果。

CALCULATION OF FORCE FIELD OF POLYATOMIC MOLECULE UDTILIZING EXPANSION SERIES OF MODEL FUNCTION IN NoRMAL COORDINATES

A method of simulating force field of polyatomic molecule with expansion series ofmodel potential function in normal coordinates is presented In.normal coordinates,the forceconstants matrix has only diagonal terms,whereas all the off-diagonal terms are zero,The wholeprocess of simulation becomes very simple. Using this method,on the level of ab initio calculation,force constants of some polyatomic molecules are obtained; They are applied to vibrational analysis.The results are better than that of the ab initio-gradient method and other ab initio method.