Dipole Polarizability of Alkali-Metal (Na, K, Rb) - Alkaline-Earth-Metal (Ca,Sr) Polar molecules - Prospects of Alignment

TL;DR

This study investigates the electronic properties, dipole moments, and polarizabilities of selected alkali-metal and alkaline-earth-metal polar molecules, highlighting their potential for alignment in external fields based on theoretical calculations.

Contribution

It provides detailed potential energy curves, spectroscopic constants, and polarizability data for specific alkali-alkaline-earth molecules using high-level quantum chemistry methods, which were previously unavailable.

Findings

Moderate permanent dipole moments identified for KCa, RbCa, KSr, RbSr.

Large polarizability anisotropy suggests suitability for molecular alignment.

Theoretical data supports potential experimental applications in molecular control.

Abstract

Electronic open-shell ground-state properties of selected alkali-metal (AM) - alkaline-earth-metal (AEM) polar molecules are investigated. We determine potential energy curves of the 2{\Sigma}+ ground state at the coupled-cluster singles and doubles with partial triples (CCSD(T)) level of electron correlation. Calculated spectroscopic constants for the isotopes (23Na, 39K, 85Rb) - (40Ca, 88Sr) are compared with available theoretical and experimental results. The variation of the permanent dipole moment (PDM), average dipole polarizability, and polarizability anisotropy with internuclear distance is determined using finite-field perturbation theory at the CCSD(T) level. Owing to moderate PDM (KCa: 1.67 D, RbCa: 1.75 D, KSr: 1.27 D, RbSr: 1.41 D) and large polarizability anisotropy (KCa: 566 a.u., RbCa: 604 a.u., KSr: 574 a.u., RbSr: 615 a.u.), KCa, RbCa, KSr, and RbSr are potential candidates for alignment and orientation in combined intense laser and external static electric fields.