| Autor: |
Benali, Anouar, Gasperich, Kevin, Jordan, Kenneth D., Applencourt, Thomas, Luo, Ye, Bennett, M. Chandler, Krogel, Jaron T., Shulenburger, Luke, Kent, Paul R. C., Loos, Pierre-François, Scemama, Anthony, Caffarel, Michel |
| Rok vydání: |
2020 |
| Předmět: |
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| Druh dokumentu: |
Working Paper |
| Popis: |
While Diffusion Monte Carlo (DMC) is in principle an exact stochastic method for \textit{ab initio} electronic structure calculations, in practice the fermionic sign problem necessitates the use of the fixed-node approximation and trial wavefunctions with approximate nodes (or zeros) must be used. This approximation introduces a variational error in the energy that potentially can be tested and systematically improved. Here, we present a computational method that produces trial wavefunctions with systematically improvable nodes for DMC calculations of periodic solids. These trial wavefunctions are efficiently generated with the configuration interaction using a perturbative selection made iteratively (CIPSI) method. A simple protocol in which both exact and approximate results for finite supercells are used to extrapolate to the thermodynamic limit is introduced. |
| Databáze: |
arXiv |
| Externí odkaz: |
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