Gaussian程序计算的一阶超极化率的符号问题

The Problem of the First-order Hyperpolarizability Sign Obtained by Gaussian Package Calculation

在明确了Gaussian程序的偶极矩和电偶极场的定义后,用静电场存在时单点计算的分子能量进行数值微分得到一阶超极化率,然后与Gaussian程序计算的一阶超极化率比较.发现Gaussian程序用polar关键词计算的超极化率的各分量应该变号.

After understanding the definitions of dipole moment and electric dipole field in Gaussian 03 package,the following procedure has been applied to calculate the first-order hyperpolarizability.By using single point calculation,the first-order hyperpolarizability has been produced by numerical differentiation of energies.When the components of the hyperpolarizability β obtained by the above two-step procedure are compared to the results calculated by using polar Keyword with Gaussian package,the authors find that the sign of the components of the first hyperpolarizability calculated by using polar keyword with Gaussian package should be reversed.