A relativistic coupled-cluster interaction potential and rovibrational constants for the xenon dimer

ABSTRACT

An accurate potential energy curve has been derived for the xenon dimer using state-of-the-art relativistic coupled-cluster theory up to quadruple excitations accounting for both basis set superposition and incompleteness errors. The data obtained is fitted to a computationally efficient extended Lennard-Jones potential form and to a modified Tang–Toennies potential function treating the short- and long-range part separately. The vibrational spectrum of Xe₂ obtained from a numerical solution of the rovibrational Schrödinger equation and subsequently derived spectroscopic constants are in excellent agreement with experimental values. We further present solid-state calculations for xenon using a static many-body expansion up to fourth-order in the xenon interaction potential including dynamic effects within the Einstein approximation. Again we find very good agreement with the experimental (face-centred cubic) lattice constant and cohesive energy.

KEYWORDS:

• Xenon many-body potential
• relativistic coupled-cluster
• spectroscopic constants
• solid-state calculations

Acknowledgements

The authors thank Dr Robert Hellmann (University of Rostock, Germany) for useful discussions. The authors wish to acknowledge the contribution of NeSI high-performance computing facilities to the results of this research. NZ's national facilities are provided by the NZ eScience Infrastructure and funded jointly by NeSI's collaborator institutions and through the Ministry of Business, Innovation and Employment's Research Infrastructure programme.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We acknowledge financial support by the Marsden Fund of the Royal Society of New Zealand [grant number MAU1409]; Alexander-von-Humboldt Foundation (Bonn, Germany); NeSI's collaborator institutions; Ministry of Business, Innovation and Employment's Research Infrastructure Programme.