Abstract
Diffusion quantum Monte Carlo (DQMC) is a powerful method for calculating the vibrational ground state of large systems but is inapplicable in general for excited states. We propose a general method for excited states, based on combining DQMC with the approximate vibrational self-consistent field (VSCF) approach; the latter is used to obtain the nodes of the excited state wavefunctions. The combined DQMC-VSCF is approximate but found high accuracy in test calculations of Ar3. DQMC-VSCF is also applied to collective mode excitations of Ar13. The method provides full spectroscopic assignment for the computed excited states through VSCF.
Original language | English |
---|---|
Pages (from-to) | 437-442 |
Number of pages | 6 |
Journal | Chemical Physics Letters |
Volume | 299 |
Issue number | 5 |
DOIs | |
State | Published - 16 Jan 1999 |