Potential Energy Curves and Generalized Oscillator Strength for Doubly Excited States of Hydrogen Molecule

TL;DR

This study calculates potential energy curves and generalized oscillator strengths for doubly excited states of H2, revealing a new dissociation pathway into hydrogen 2s atoms using advanced MRCI methods.

Contribution

It provides the first identification of a molecular state dissociating into hydrogen 2s atoms and presents detailed potential energy and oscillator strength data for doubly excited H2 states.

Findings

Identification of a new dissociation pathway into hydrogen 2s atoms.

Potential energy curves for doubly excited states of H2.

Generalized oscillator strength data for three doubly excited states.

Abstract

In this paper we report calculations of potential energy curves in the $1.2 a.u.\le R\le100 a.u.$ range at Multireference Configuration Interaction (MRCI) level for doubly excited states of the H$_2$ molecule. We have focused on the $Q_2$ states which lie between the second and third ionization thresholds of H$_2^+$ molecular ion, i.e., $^2\Sigma_u^+$ state in which lie the H(2l) + H(2l') dissociation channels. The MRCI approach allowed us to successfully identify for the first time the molecular state which dissociates into hydrogen atoms at 2s state. Further, Generalized Oscillator Strength as a function of transferred momentum for three doubly excited states is also presented. (Some figures in this article are in colour only in the electronic version)