Theory

ADFT: Auxiliary density functional theory is a practical way to realize efficient density functional theory (DFT) calculations on the Kohn-Sham approach but avoiding the use of 4-index electron repulsion integrals (4-ERIs). We have contributed to the efficient evaluation of exchange-correlation integrals and to the generalization to multicomponent ADFT (MADFT).

ADPT: Auxiliary density perturbation theory is a reformulation of coupled perturbed Kohn-Sham equations which is achieved by inverting the response of the variational fitting of the Coulomb potential. This particular formulation was developed by us from its original version and has been further extended to apply it in linear and quadratic response on different frameworks and for different types of perturbations.

Green's functions including one-particle and multiple-particle propagator methods. Our group has contributed to the development of multicomponent versions of the electron propagator and its connection to ADFT/ADPT formulations. This includes the efficient evaluation of self-energy by exploiting auxiliary functions, the construction of the generalized one-particle propagator applied to electrons, protons and positrons in multicomponent post-Hartree-Fock calculations. Currently we are working on multiple scattering theory.