Highly polar molecules consisting of a copper or silver atom interacting with an alkali-metal or alkaline-earth-metal atom

TL;DR

This paper provides a comprehensive theoretical analysis of highly polar diatomic molecules involving copper or silver with alkali or alkaline-earth metals, predicting their properties and potential applications in ultracold physics and precision measurements.

Contribution

It introduces detailed ab initio calculations of potential energy, dipole moments, and spectroscopic constants for these molecules, highlighting their strong binding and large dipole moments.

Findings

Molecules are strongly bound with large electric dipole moments.

Highly excited vibrational levels exhibit maximal dipole moments exceeding 13 Debye.

Results include data for Cu$_2$, Ag$_2$, and CuAg molecules.

Abstract

We theoretically investigate the properties of highly polar diatomic molecules containing $^2S$-state transition-metal atoms. We calculate potential energy curves, permanent electric dipole moments, spectroscopic constants, and leading long-range dispersion-interaction coefficients for molecules consisting of either a Cu or Ag atom interacting with an alkali-metal (Li, Na, K, Rb, Cs, Fr) or alkaline-earth-metal (Be, Mg, Ca, Sr, Ba, Ra) atom. We use ab initio electronic structure methods, such as the coupled cluster and configuration interaction ones, with large Gaussian basis sets and small-core relativistic energy-consistent pseudopotentials. We predict that the studied molecules in the ground electronic state are strongly bound with highly polarized covalent or ionic bonds resulting in very large permanent electric dipole moments. We find that highly excited vibrational levels have maximal electric dipole moments, e.g., exceeding 13$\,$debye for CsAg and 6$\,$debye for BaAg. Results for Cu$_2$, Ag$_2$, and CuAg are also reported. The studied molecules may find application in ultracold dipolar many-body physics, controlled chemistry, or precision measurement experiments.