Quantum Monte Carlo method using phase-free random walks with Slater determinants

摘要

We develop a quantum Monte Carlo method for many fermions that allows the useof any one-particle basis. It projects out the ground state by random walks inthe space of Slater determinants. An approximate approach is formulated tocontrol the phase problem with a trial wave function $|\Psi_T>$. Usingplane-wave basis and non-local pseudopotentials, we apply the method to Siatom, dimer, and 2, 16, 54 atom (216 electrons) bulk supercells. Single Slaterdeterminant wave functions from density functional theory calculations wereused as $|\Psi_T>$ with no additional optimization. The calculated bindingenergy of Si2 and cohesive energy of bulk Si are in excellent agreement withexperiments and are comparable to the best existing theoretical results.