Pfaffian pairing wave functions in electronic-structure quantum Monte Carlo simulations

We investigate the accuracy of trial wave functions for quantum Monte Carlo based on Pfaffian functional form with singlet and triplet pairing. Using a set of first row atoms and molecules we find that these wave functions provide very consistent and systematic behavior in recovering the correlation...

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Bibliographic Details
Published in:Physical review letters Vol. 96; no. 13; p. 130201
Main Authors: Bajdich, M, Mitas, L, Drobný, G, Wagner, L K, Schmidt, K E
Format: Journal Article
Language:English
Published: United States 07-04-2006
Online Access:Get full text
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Summary:We investigate the accuracy of trial wave functions for quantum Monte Carlo based on Pfaffian functional form with singlet and triplet pairing. Using a set of first row atoms and molecules we find that these wave functions provide very consistent and systematic behavior in recovering the correlation energies on the level of 95%. In order to get beyond this limit we explore the possibilities of multi-Pfaffian pairing wave functions. We show that a small number of Pfaffians recovers another large fraction of the missing correlation energy comparable to the larger-scale configuration interaction wave functions. We also find that Pfaffians lead to substantial improvements in fermion nodes when compared to Hartree-Fock wave functions.
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ISSN:0031-9007
1079-7114
DOI:10.1103/physrevlett.96.130201