Dynamical pseudopotentials

by Mr Matteo Quinzi (EPFL)

Wednesday 29 Oct 2025, 12:00 → 13:00 Europe/Zurich

OVGA/200

Ab initio pseudopotentials can in principle reproduce the scattering properties of the all-electron core at a finite set of arbitrarily chosen energies, but the faithful description of high-energy scattering states is often hindered by practical limitations and ill-conditioning. We present a novel approach for generating first-principles dynamical  pseudopotentials, in which the flexibility of an energy-dependent construction is exploited to systematically improve transferability at the level of accuracy of density-functional theory. We first show that this energy dependence generalizes the norm-conservation condition [1], introducing soft pseudo-orbitals [2] and dynamical augmentation charges related to the derivative of the pseudopotential. We then introduce an effective embedding scheme to build pseudopotentials within a sum-over poles representation, enabling efficient electronic-structure calculations in conjunction with the algorithmic-inversion method for the exact solution of the Dyson equation [3,4]. Notably, the number of projectors in the nonlocal pseudopotential is disentangled from the number of reference energies at which scattering properties are reproduced, allowing for a systematic improvement of transferability without sacrificing numerical efficiency.

[1] D. R. Hamann, M. Schlüter and C. Chiang, Phys. Rev. Lett. 43, 1494 (1979)

[2] D. Vanderbilt, Phys. Rev. B 41, 7892(R) (1990)

[3] T. Chiarotti, N. Marzari and A. Ferretti, Phys. Rev. Research 4, 013242 (2022)

[4] T. Chiarotti, A. Ferretti and N. Marzari, Phys. Rev. Research 6, L032023 (2024)