Seminar on 9 May 2019

Department of Physics, University of Ostrava, Ostrava, Czech Republic; ATRI, Slovak University of Technology, Trnava, Slovakia
Fractional charge by fixed-node diffusion Monte Carlo
at 13:00 in Seminar room F052

Fixed-node diffusion Monte Carlo (FNDMC) is a stochastic quantum many-body method that has a great potential in electronic structure theory. We examine how FNDMC satisfies exact constraints, linearity and derivative discontinuity of total energy E(N) vs. fractional electron number N, if combined with mean-field trial wave functions that miss such features. H and Cl atoms with fractional charge reveal that FNDMC is well able to restore the piecewise linearity of E(N). The method uses ensemble and projector ingredients to achieve the correct charge localization. Water-solvated Cl−complex illustrates superior performance of FNDMC for charged noncovalent systems.
See preprint at arXiv:1903.12378 [physics.chem-ph].