ct8b00679_si_001.pdf (147.4 kB)
Multilevel Approach for Direct VSCF/VCI MULTIMODE Calculations with Applications to Large “Zundel” Cations
journal contribution
posted on 2018-11-14, 00:00 authored by Jake A. Tan, Jer-Lai KuoWe test existing efficient schemes
for the “direct-dynamics”
approach in building a potential energy surface (PES) in the code
MULTIMODE. These are (1) the n-mode representation
(nMR) approach to the PES, (2) the exploitation of the normal mode’s
symmetry to reduce the computational effort in constructing the PES,
(3) the use of sparse grids for fitting the n-mode
potentials, and (4) different levels of ab initio theory for these
potentials. These schemes are applied to a four-dimensional calculation
for the proton-bound methanol dimer (CH3OH)2H+. In addition to the major reduction in complexity obtained
by considering only four modes, the combination of these schemes leads
to a significant reduction in the computational effort without any
major loss of accuracy. VSCF/VCI test calculations are presented for
(CH3OH)2H+.