Rotational and rotationless states of weakly-bound molecules

TL;DR

This paper derives simple formulas to determine the rotational states and constants of weakly-bound diatomic molecules using long-range potential data, aiding the study of halo molecules.

Contribution

It introduces new, accurate formulas for rotational states and constants based solely on long-range potential, applicable to halo molecules.

Findings

Derived formulas for rotational states and constants

Provided criterion for rotationless vibrational levels

Applicable to halo molecules

Abstract

By making use of the quantization rule of Raab and Friedrich [P. Raab and H. Friedrich, Phys. Rev. A 78, 022707 (2008)], we derive simple and accurate formulae for the number of rotational states supported by a weakly-bound vibrational level of a diatomic molecule and the rotational constants of any such levels up to the threshold, and provide a criterion for determining whether a given weakly-bound vibrational level is rotationless. The results depend solely on the long-range part of the molecular potential and are applicable to halo molecules.