Alchemical perturbation density functional theory

Guido Von Rudorff - University of Basel

Friday 14th December 2018
Time: 1pm
Venue: Nyholm Room, Christopher Ingold Building, UCL Chemistry
Contact: Karen Stoneham
Tel: 0207 679 7306

We introduce an electron density functional approximation which is based on alchemical perturbation theory. The electron density of {\em any} given iso-electronic target system is approximated within a Taylor series using alchemical perturbations of a suitable reference system. The associated energy functional is an approximation to thermodynamic integration, requiring only perturbed reference electron densities, no self-consistent field equations are necessary to estimate energies and electron densities. The approach works best when reference and target share the same geometry. The approach is exemplified for the toy system He and H , as well as for diatomics N , CO, and BF, and our calculations indicate rapid convergence with perturbation order. Numerical evidence for perturbed reference electron densities evaluated at several levels of theory (LDA, GGA, hybrid, and CCSD) suggest that typical DFT accuracy can be outperformed, at negligible cost. Electronic ground state properties considered include covalent bonding potentials, atomic forces, as well as dipole and quadropole moments.

Bio: M.Sc. Physics from Freie Universität Berlin, Germany, with Prof. Sebastiani. PhD on large-scale DFT calculations on transition metal oxide/water interfaces with Prof. Blumberger at UCL. Now postdoc at University of Basel, Switzerland with Prof. von Lilienfeld working on alchemical DFT and machine learning of reaction barriers.

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