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Title: Accurate nonrelativistic ground-state energies of 3d transition metal atoms

Abstract

We present accurate nonrelativistic ground-state energies of the transition metal atoms of the 3d series calculated with Fixed-Node Diffusion Monte Carlo (FN-DMC). Selected multi-determinantal expansions obtained with the CIPSI (Configuration Interaction using a Perturbative Selection made Iteratively) method and including the most prominent determinants of the full configuration interaction expansion are used as trial wavefunctions. Using a maximum of a few tens of thousands determinants, fixed-node errors on total DMC energies are found to be greatly reduced for some atoms with respect to those obtained with Hartree-Fock nodes. To the best of our knowledge, the FN-DMC/(CIPSI nodes) ground-state energies presented here are the lowest variational total energies reported so far. They differ from the recently recommended non-variational values of McCarthy and Thakkar [J. Chem. Phys. 136, 054107 (2012)] only by a few percents of the correlation energy. Thanks to the variational property of FN-DMC total energies, our results provide exact lower bounds for the absolute value of all-electron correlation energies, |E{sub c}|.

Authors:
; ; ;  [1]
  1. Lab. Chimie et Physique Quantiques, CNRS-Université de Toulouse, Toulouse (France)
Publication Date:
OSTI Identifier:
22415407
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; ATOMS; CONFIGURATION INTERACTION; DIFFUSION; ELECTRON CORRELATION; GROUND STATES; HARTREE-FOCK METHOD; ITERATIVE METHODS; MONTE CARLO METHOD; TRANSITION ELEMENTS; VARIATIONAL METHODS

Citation Formats

Scemama, A., Applencourt, T., Giner, E., and Caffarel, M. Accurate nonrelativistic ground-state energies of 3d transition metal atoms. United States: N. p., 2014. Web. doi:10.1063/1.4903985.
Scemama, A., Applencourt, T., Giner, E., & Caffarel, M. Accurate nonrelativistic ground-state energies of 3d transition metal atoms. United States. doi:10.1063/1.4903985.
Scemama, A., Applencourt, T., Giner, E., and Caffarel, M. Sun . "Accurate nonrelativistic ground-state energies of 3d transition metal atoms". United States. doi:10.1063/1.4903985.
@article{osti_22415407,
title = {Accurate nonrelativistic ground-state energies of 3d transition metal atoms},
author = {Scemama, A. and Applencourt, T. and Giner, E. and Caffarel, M.},
abstractNote = {We present accurate nonrelativistic ground-state energies of the transition metal atoms of the 3d series calculated with Fixed-Node Diffusion Monte Carlo (FN-DMC). Selected multi-determinantal expansions obtained with the CIPSI (Configuration Interaction using a Perturbative Selection made Iteratively) method and including the most prominent determinants of the full configuration interaction expansion are used as trial wavefunctions. Using a maximum of a few tens of thousands determinants, fixed-node errors on total DMC energies are found to be greatly reduced for some atoms with respect to those obtained with Hartree-Fock nodes. To the best of our knowledge, the FN-DMC/(CIPSI nodes) ground-state energies presented here are the lowest variational total energies reported so far. They differ from the recently recommended non-variational values of McCarthy and Thakkar [J. Chem. Phys. 136, 054107 (2012)] only by a few percents of the correlation energy. Thanks to the variational property of FN-DMC total energies, our results provide exact lower bounds for the absolute value of all-electron correlation energies, |E{sub c}|.},
doi = {10.1063/1.4903985},
journal = {Journal of Chemical Physics},
number = 24,
volume = 141,
place = {United States},
year = {Sun Dec 28 00:00:00 EST 2014},
month = {Sun Dec 28 00:00:00 EST 2014}
}