Systematic Comparison and Cross-validation of Fixed-Node Diffusion Monte Carloand Phaseless Auxiliary-Field Quantum Monte Carlo in Solids
ORAL
Abstract
Diffusion Monte Carlo (DMC) and Auxiliary Field Quantum Monte Carlo (AFQMC) can both have their approximations systematically improved by applying successively more accurate trial wavefunctions. In this work we assess the feasibility of determining exact total energies for solid state Hamiltonians by studying primitive cells of four representative
materials, Al, LiF and Carbon-diamond. Specifically, we utilize multideterminant trial wavefunctions generated via selective CI techniques with various sizes of single particle basis. Attention is paid to the rate at which the error decreases as the trial wavefunction includes more determinants and the increase of the basis size. In this way, we are able to compare both DMC and AFQMC on equal terms at identical levels of approximation.
https://doi.org/10.1103/PhysRevB.102.161104
materials, Al, LiF and Carbon-diamond. Specifically, we utilize multideterminant trial wavefunctions generated via selective CI techniques with various sizes of single particle basis. Attention is paid to the rate at which the error decreases as the trial wavefunction includes more determinants and the increase of the basis size. In this way, we are able to compare both DMC and AFQMC on equal terms at identical levels of approximation.
https://doi.org/10.1103/PhysRevB.102.161104
*Supported by US DOE BES, Mat. Sci. and Engn. Div., Comput. Mat. Sci. Prog. and Center for Predictive Simulation of
Functional Materials. Calculations used resources of the Argonne Leadership Computing Facility, a DOE Office of Science User Facility supported under Contract DE-AC02-06CH11357 and the Livermore Computing Facilities. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.
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Presenters
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Anouar Benali
- Argonne National Laboratory
- Computational Science Division, Argonne National Laboratory