Trapping and migration of P-state atoms in rare gas solids: effect of angular momentum anisotropy for model O(³P) and C(³P) atoms

Abstract

Classical simulations of model O(${}^3$P) atom isolated in Ar, Kr and Xe crystals with the variable magnitude and sign of the angular momentum anisotropy are performed. The guest–host interaction anisotropy remarkably affects the structure of the atomic trapping sites and the barriers to the temperature-induced atomic mobility. For interstitial trapping, inversion of anisotropy induces a kind of critical phenomenon, which transforms the migration path saddle point to a minimum and another saddle. As a result, a new peculiar axially symmetric interstitial site is formed with the migration barrier reduced. Preliminary ab initio-based study of the C(${}^3$P) atom, whose interactions with Ar, Kr and Xe have the anisotropy opposite to oxygen, fully confirms the model analysis. Our results emphasise profound effect of the angular momentum anisotropy on the structure and dynamics of the open-shell atoms at matrix isolation.

GRAPHICAL ABSTRACT

Keywords:

• Interaction anisotropy
• matrix isolation
• potential energy surfaces
• matrix-isolated atoms

Acknowledgments

The authors thank Prof. Claudio Lenz Cesar for discussion on the matrix isolation of atomic carbon and anonymous referees for instructive comments. A. A. B. is deeply indebted to Oleg Vasyutinskii for almost 30 years of friendship, discussions and inspirations, for the present work as well.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The financial support by the Russian Science Foundation under the project no. 17-13-01466 is gratefully acknowledged.