Non-Adiabatic Potential-Energy Surfaces by Constrained Density-Functional Theory

TL;DR

This paper introduces a constrained density-functional theory method to compute non-adiabatic potential-energy surfaces, enabling detailed study of chemical processes involving electron confinement to specific subsystems.

Contribution

The authors develop a locally-constrained DFT approach to calculate non-adiabatic PESs for specific charge and spin states, advancing the analysis of complex chemical interactions.

Findings

Successfully calculated non-adiabatic PESs for atom scattering and molecule-surface interactions.

Demonstrated the method on sodium-chlorine scattering, chlorine-metal cluster interaction, and oxygen dissociation on Al(111).

Showed the approach's capability to handle various non-adiabatic phenomena.

Abstract

Non-adiabatic effects play an important role in many chemical processes. In order to study the underlying non-adiabatic potential-energy surfaces (PESs), we present a locally-constrained density-functional theory approach, which enables us to confine electrons to sub-spaces of the Hilbert space, e.g. to selected atoms or groups of atoms. This allows to calculate non-adiabatic PESs for defined charge and spin states of the chosen subsystems. The capability of the method is demonstrated by calculating non-adiabatic PESs for the scattering of a sodium and a chlorine atom, for the interaction of a chlorine molecule with a small metal cluster, and for the dissociation of an oxygen molecule at the Al(111) surface.