Theory of dissociative recombination of a linear triatomic ion with permanent electric dipole moment: Study of HCO$^{+}$

TL;DR

This paper develops a theoretical model for the dissociative recombination of triatomic ions with large permanent dipole moments, specifically addressing the HCO$^+$ ion, by explicitly including electric dipole effects using generalized quantum defect theory.

Contribution

It introduces the first application of generalized quantum defect theory to model dissociative recombination of molecular ions with permanent dipoles, improving understanding of HCO$^+$ recombination.

Findings

Explicit inclusion of electric dipole effects alters cross-section calculations.

Theoretical cross-sections better match experimental data.

First application of generalized quantum defect theory to this problem.

Abstract

We present a theoretical description of dissociative recombination of triatomic molecular ions having large permanent dipole moments. The study has been partly motivated by a discrepancy between experimental and theoretical cross-sections for dissociative recombination of the HCO$^+$ ion. The HCO$^{+}$ ion has a considerable permanent dipole moment ($D\approx$4 debye), which has not been taken explicitly into account in previous theoretical studies. In the present study, we include explicitly the effect of the permanent electric dipole on the dynamics of the incident electron using the generalized quantum defect theory, and we present the resulting cross section obtained. This is the first application of generalized quantum defect theory to the dissociative recombination of molecular ions.