Communication: fixed-node errors in quantum Monte Carlo: interplay of electron density and node nonlinearities.
J Chem Phys
; 140(4): 041102, 2014 Jan 28.
Article
em En
| MEDLINE
| ID: mdl-25669493
ABSTRACT
We elucidate the origin of large differences (two-fold or more) in the fixed-node errors between the first- vs second-row systems for single-configuration trial wave functions in quantum Monte Carlo calculations. This significant difference in the valence fixed-node biases is studied across a set of atoms, molecules, and also Si, C solid crystals. We show that the key features which affect the fixed-node errors are the differences in electron density and the degree of node nonlinearity. The findings reveal how the accuracy of the quantum Monte Carlo varies across a variety of systems, provide new perspectives on the origins of the fixed-node biases in calculations of molecular and condensed systems, and carry implications for pseudopotential constructions for heavy elements.
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MEDLINE
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En
Ano de publicação:
2014
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Article