Premium
Two aspects of quantum monte carlo: Determination of accurate wavefunctions and determination of potential energy surfaces of molecules
Author(s) -
Umrigar C. J.
Publication year - 2009
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560360826
Subject(s) - monte carlo method , wave function , quantum monte carlo , variational monte carlo , statistical physics , dynamic monte carlo method , monte carlo method in statistical physics , energy (signal processing) , monte carlo molecular modeling , quantum , physics , monte carlo integration , hybrid monte carlo , quantum mechanics , mathematics , statistics , markov chain monte carlo
Abstract Two aspects of quantum Monte Carlo are discussed. First, we review a procedure for obtaining trial wavefunctions for use in quantum Monte Carlo simulations that have both smaller statistical errors and improved expectation values than commonly used functions. Second, we present a correlated sampling approach for calculating energy differences in variational Monte Carlo much more accurately than the values of the energies. This method is used to calculate the potential energy surfaces of H 2 and BH. In the case of BH, at bond lengths 10% different from the reference geometry, the reduced statistical error in the relative energy results in a factor of 3000 saving in computer time.