Application of the Multi-Center Partition Method to Construct the Potential Energy Surface of H₃

Abstract

The potential energy surface plays an important role in studying molecular reaction dynamics. In this work, a new method, namely the "multi-center partition" method, is proposed to construct the potential energy surface of H 3 . The optimized function is first determined by comparing the London-Eyring-Polanyi-Sato (LEPS) potential, the many-body expansion potential, and the permutation-invariant polynomial potential. This comparison shows that the permutation-invariant polynomial fitting proposed by Bowman is the most efficient method for describing the topology of the H 3 system. The quasi-classical trajectory method is used to analyze the rationality of those potential energy surfaces. By combining the multi-center partition method with the permutation-invariant polynomial method, the accuracy of the H 3 molecular potential energy surface is greatly improved and could possibly be used in the fitting of potential energy surfaces in other systems.