Accurate nonrelativistic groundstate energies of 3d transition metal atoms
Abstract
We present accurate nonrelativistic groundstate energies of the transition metal atoms of the 3d series calculated with FixedNode Diffusion Monte Carlo (FNDMC). Selected multideterminantal 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, fixednode errors on total DMC energies are found to be greatly reduced for some atoms with respect to those obtained with HartreeFock nodes. To the best of our knowledge, the FNDMC/(CIPSI nodes) groundstate energies presented here are the lowest variational total energies reported so far. They differ from the recently recommended nonvariational 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 FNDMC total energies, our results provide exact lower bounds for the absolute value of allelectron correlation energies, E{sub c}.
 Authors:
 Lab. Chimie et Physique Quantiques, CNRSUniversité 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; HARTREEFOCK METHOD; ITERATIVE METHODS; MONTE CARLO METHOD; TRANSITION ELEMENTS; VARIATIONAL METHODS
Citation Formats
Scemama, A., Applencourt, T., Giner, E., and Caffarel, M.. Accurate nonrelativistic groundstate 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 groundstate energies of 3d transition metal atoms. United States. doi:10.1063/1.4903985.
Scemama, A., Applencourt, T., Giner, E., and Caffarel, M.. 2014.
"Accurate nonrelativistic groundstate energies of 3d transition metal atoms". United States.
doi:10.1063/1.4903985.
@article{osti_22415407,
title = {Accurate nonrelativistic groundstate energies of 3d transition metal atoms},
author = {Scemama, A. and Applencourt, T. and Giner, E. and Caffarel, M.},
abstractNote = {We present accurate nonrelativistic groundstate energies of the transition metal atoms of the 3d series calculated with FixedNode Diffusion Monte Carlo (FNDMC). Selected multideterminantal 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, fixednode errors on total DMC energies are found to be greatly reduced for some atoms with respect to those obtained with HartreeFock nodes. To the best of our knowledge, the FNDMC/(CIPSI nodes) groundstate energies presented here are the lowest variational total energies reported so far. They differ from the recently recommended nonvariational 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 FNDMC total energies, our results provide exact lower bounds for the absolute value of allelectron correlation energies, E{sub c}.},
doi = {10.1063/1.4903985},
journal = {Journal of Chemical Physics},
number = 24,
volume = 141,
place = {United States},
year = 2014,
month =
}

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