TCP Seminar: Matej Ditte

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.

Matej Ditte is a research assistant at the Department of Physics, University of Ostrava, in group of Matus Dubecky. He has recently graduated from the Comenius University in Bratislava in Solid State Physics (in collaboration with Slovak Academy of Sciences). Most of his research has been focused on many-body electronic structure theory and computations and continuum quantum Monte Carlo techniques. His experience covers excited states and non-covalent interactions in molecular and extended systems, as well as modeling of fractional charge systems. He is currently a co-author of two scientific publications [1,2].

[1] Dubecký M, Jurečka P, Mitas L, Ditte M, Fanta R: Toward Accurate Hydrogen Bonds by Scalable

Quantum Monte Carlo. J. Chem. Theory Comput., 15(6), 3552-3557, 2019.

[2] M. Ditte, M. Dubecky: Fractional charge by fixed-node diffusion Monte Carlo, submitted

(arXiv:1903.12378)