A general code for fitting global potential energy surfaces via CHIPR method: Triatomic molecules

A general program to fit global potential energy surfaces of ABC, AB2, and A3 triatomic molecules to ab initio points is reported. It is based on the Combined-Hyperbolic-Inverse-Power-Representation (CHIPR) method. The final form describes all dissociating fragments, long-range and valence interactions, while warranting the system permutational symmetry. The code yields as output a Fortran 90 subroutine that readily evaluates the potential and gradient at any arbitrary geometry.

本文报道了一种可将ABC、AB₂及A₃型三原子分子的全局势能面拟合至从头算（ab initio）数据点的通用程序。该程序基于组合双曲反幂表示（Combined-Hyperbolic-Inverse-Power-Representation，CHIPR）方法。最终的拟合形式可完整描述所有解离片段、长程相互作用与价相互作用，同时严格保证体系的置换对称性。该代码输出一段Fortran 90子程序，可便捷计算任意几何构型下的势能与梯度。