Dipolar Radicals in Crossed Electric and Magnetic Fields

TL;DR

This paper develops a theoretical framework for understanding paramagnetic dipolar radicals in arbitrary crossed electric and magnetic fields, introducing a new quantum number basis called 'Hund's case-X' for strong field regimes.

Contribution

It introduces the 'Hund's case-X' basis, a new quantum number set for molecules in arbitrary crossed fields, enabling exact diagonalization of the Hamiltonian.

Findings

Exact diagonalization of the Hamiltonian in crossed fields.

Definition of quantum numbers based on the projection along a field-determined axis.

Identification of a new basis for strong field conditions.

Abstract

Paramagnetic, dipolar Hund's case-a radicals are considered in the presence of arbitrary, non-collinear combinations of electric and magnetic fields. The field-dependent part of the Hamiltonian is found to be exactly diagonalizable, and described by quantum numbers given by the projection of the molecule's total angular momentum along a space-fixed axis that is determined by both the fields and the electric and magnetic dipole moments of the molecule. In cases of strong fields, this procedure identifies a set of quantum numbers for the molecule in crossed fields. We dub this set a "Hund's case-X" basis.