Stark Ionization of Atoms and Molecules within Density Functional Resonance Theory

TL;DR

This paper introduces a novel method within density functional theory to accurately compute the energetics and lifetimes of atomic and molecular resonances under electric fields using complex scaling techniques.

Contribution

It develops a self-consistent formalism for resonance properties in DFT using complex densities, potentials, and wavefunctions, extending existing algorithms.

Findings

Successfully calculated ionization rates for various atoms and molecules.

Demonstrated the method with local density approximation and exact exchange.

Extended DFT to include resonance states under external electric fields.

Abstract

We show that the energetics and lifetimes of resonances of finite systems under an external electric field can be captured by Kohn--Sham density functional theory (DFT) within the formalism of uniform complex scaling. Properties of resonances are calculated self-consistently in terms of complex densities, potentials and wavefunctions using adapted versions of the known algorithms from DFT. We illustrate this new formalism by calculating ionization rates using the complex-scaled local density approximation and exact exchange. We consider a variety of atoms (H, He, Li and Be) as well as the hydrogen molecule. Extensions are briefly discussed.