Computing vibrational energy levels of CH4 with a Smolyak collocation method

作者：Avila Gustavo^*; Carrington Tucker Jr

来源：Journal of Chemical Physics, 2017, 147(14): 144102.

DOI：10.1063/1.4999153

In this paper, we demonstrate that it is possible to apply collocation to compute vibrational energy levels of a five-atom molecule using an exact kinetic energy operator (with cross terms and coordinate-dependent coefficients). This is made possible by using (1) a pruned basis of products of univariate functions; (2) a Smolyak grid made from nested sequences of grids for each coordinate; (3) a collocation method that obviates the need to solve a generalized eigenvalue problem; (4) an efficient sequential transformation between the (nondirect product) grid and the (nondirect product) basis representations; and (5) hierarchical univariate functions that make it possible to avoid storing large intermediate vectors. The accuracy of the method is confirmed by computing 500 vibrational energy levels of methane. Published by AIP Publishing.

• 出版日期2017-10-14