Stochastic algorithm for sizeextensive vibrational selfconsistent field methods on fully anharmonic potential energy surfaces
Abstract
A stochastic algorithm based on Metropolis Monte Carlo (MC) is presented for the sizeextensive vibrational selfconsistent field methods (XVSCF(n) and XVSCF[n]) for anharmonic molecular vibrations. The new MCXVSCF methods substitute stochastic evaluations of a small number of highdimensional integrals of functions of the potential energy surface (PES), which is sampled on demand, for diagrammatic equations involving highorder anharmonic force constants. This algorithm obviates the need to evaluate and store any highdimensional partial derivatives of the potential and can be applied to the fully anharmonic PES without any Taylorseries approximation in an intrinsically parallelizable algorithm. The MCXVSCF methods reproduce deterministic XVSCF calculations on the same Taylorseries PES in all energies, frequencies, and geometries. Calculations using the fully anharmonic PES evaluated on the fly with electronic structure methods report anharmonic effects on frequencies and geometries of much greater magnitude than deterministic XVSCF calculations, reflecting an underestimation of anharmonic effects in a Taylorseries approximation to the PES.
 Authors:
 Department of Chemistry, University of Illinois at UrbanaChampaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States)
 (Japan)
 Publication Date:
 OSTI Identifier:
 22415408
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 24; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALGORITHMS; APPROXIMATIONS; ELECTRONIC STRUCTURE; EVALUATION; INTEGRALS; MONTE CARLO METHOD; POTENTIAL ENERGY; POTENTIALS; SELFCONSISTENT FIELD; STOCHASTIC PROCESSES; SURFACES
Citation Formats
Hermes, Matthew R., Hirata, So, Email: sohirata@illinois.edu, and CREST, Japan Science and Technology Agency, 418 Honcho, Kawaguchi, Saitama 3320012. Stochastic algorithm for sizeextensive vibrational selfconsistent field methods on fully anharmonic potential energy surfaces. United States: N. p., 2014.
Web. doi:10.1063/1.4904220.
Hermes, Matthew R., Hirata, So, Email: sohirata@illinois.edu, & CREST, Japan Science and Technology Agency, 418 Honcho, Kawaguchi, Saitama 3320012. Stochastic algorithm for sizeextensive vibrational selfconsistent field methods on fully anharmonic potential energy surfaces. United States. doi:10.1063/1.4904220.
Hermes, Matthew R., Hirata, So, Email: sohirata@illinois.edu, and CREST, Japan Science and Technology Agency, 418 Honcho, Kawaguchi, Saitama 3320012. 2014.
"Stochastic algorithm for sizeextensive vibrational selfconsistent field methods on fully anharmonic potential energy surfaces". United States.
doi:10.1063/1.4904220.
@article{osti_22415408,
title = {Stochastic algorithm for sizeextensive vibrational selfconsistent field methods on fully anharmonic potential energy surfaces},
author = {Hermes, Matthew R. and Hirata, So, Email: sohirata@illinois.edu and CREST, Japan Science and Technology Agency, 418 Honcho, Kawaguchi, Saitama 3320012},
abstractNote = {A stochastic algorithm based on Metropolis Monte Carlo (MC) is presented for the sizeextensive vibrational selfconsistent field methods (XVSCF(n) and XVSCF[n]) for anharmonic molecular vibrations. The new MCXVSCF methods substitute stochastic evaluations of a small number of highdimensional integrals of functions of the potential energy surface (PES), which is sampled on demand, for diagrammatic equations involving highorder anharmonic force constants. This algorithm obviates the need to evaluate and store any highdimensional partial derivatives of the potential and can be applied to the fully anharmonic PES without any Taylorseries approximation in an intrinsically parallelizable algorithm. The MCXVSCF methods reproduce deterministic XVSCF calculations on the same Taylorseries PES in all energies, frequencies, and geometries. Calculations using the fully anharmonic PES evaluated on the fly with electronic structure methods report anharmonic effects on frequencies and geometries of much greater magnitude than deterministic XVSCF calculations, reflecting an underestimation of anharmonic effects in a Taylorseries approximation to the PES.},
doi = {10.1063/1.4904220},
journal = {Journal of Chemical Physics},
number = 24,
volume = 141,
place = {United States},
year = 2014,
month =
}

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