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Title: Auxiliary-Field Quantum Monte Carlo Simulations of Strongly-Correlated Molecules and Solids

Abstract

We propose a method of implementing projected wave functions for second-quantized auxiliary-field quantum Monte Carlo (AFQMC) techniques. The method is based on expressing the two-body projector as one-body terms coupled to binary Ising fields. To benchmark the method, we choose to study the two-dimensional (2D) one-band Hubbard model with repulsive interactions using the constrained-path MC (CPMC). The CPMC uses a trial wave function to guide the random walks so that the so-called fermion sign problem can be eliminated. The trial wave function also serves as the importance function in Monte Carlo sampling. As such, the quality of the trial wave function has a direct impact to the efficiency and accuracy of the simulations.

Authors:
 [1];  [1]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1335769
Report Number(s):
LLNL-SR-708821
TRN: US1701387
DOE Contract Number:  
AC52-07NA27344
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; WAVE FUNCTIONS; MONTE CARLO METHOD; COMPUTERIZED SIMULATION; HUBBARD MODEL; TWO-DIMENSIONAL SYSTEMS; CORRELATIONS; TWO-BODY PROBLEM; MOLECULES; RANDOMNESS; SOLIDS; ACCURACY; BENCHMARKS; EFFICIENCY; PROJECTION OPERATORS; SECOND QUANTIZATION; IMPLEMENTATION

Citation Formats

Chang, C., and Morales, M. A.. Auxiliary-Field Quantum Monte Carlo Simulations of Strongly-Correlated Molecules and Solids. United States: N. p., 2016. Web. doi:10.2172/1335769.
Chang, C., & Morales, M. A.. Auxiliary-Field Quantum Monte Carlo Simulations of Strongly-Correlated Molecules and Solids. United States. doi:10.2172/1335769.
Chang, C., and Morales, M. A.. Thu . "Auxiliary-Field Quantum Monte Carlo Simulations of Strongly-Correlated Molecules and Solids". United States. doi:10.2172/1335769. https://www.osti.gov/servlets/purl/1335769.
@article{osti_1335769,
title = {Auxiliary-Field Quantum Monte Carlo Simulations of Strongly-Correlated Molecules and Solids},
author = {Chang, C. and Morales, M. A.},
abstractNote = {We propose a method of implementing projected wave functions for second-quantized auxiliary-field quantum Monte Carlo (AFQMC) techniques. The method is based on expressing the two-body projector as one-body terms coupled to binary Ising fields. To benchmark the method, we choose to study the two-dimensional (2D) one-band Hubbard model with repulsive interactions using the constrained-path MC (CPMC). The CPMC uses a trial wave function to guide the random walks so that the so-called fermion sign problem can be eliminated. The trial wave function also serves as the importance function in Monte Carlo sampling. As such, the quality of the trial wave function has a direct impact to the efficiency and accuracy of the simulations.},
doi = {10.2172/1335769},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Nov 10 00:00:00 EST 2016},
month = {Thu Nov 10 00:00:00 EST 2016}
}

Technical Report:

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