Classical versus quantum structures: the case of pyramidal molecules

TL;DR

This paper analyzes a model of pyramidal molecules interacting via dipole-dipole forces, explaining pressure-induced changes in molecular tunneling and localization, with a focus on stability aspects and experimental observations.

Contribution

It extends previous work by examining the stability of the model and its implications for molecular behavior under varying pressure conditions.

Findings

Model explains the pressure shift of the inversion line in ammonia gases

Molecules become localized in classical configurations at high pressure

The stability analysis supports the model's validity under different conditions

Abstract

In a previous paper we proposed a model to describe a gas of pyramidal molecules interacting via dipole-dipole interactions. The interaction modifies the tunneling properties between the classical equilibrium configurations of the single molecule and, for sufficiently high pressure, the molecules become localized in these classical configurations. The model explains quantitatively the shift to zero-frequency of the inversion line observed upon increase of the pressure in a gas of ammonia or deuterated ammonia. Here we analyze further the model especially with respect to stability questions.