Spin-polarized alkali-metal trimers revisited

TL;DR

This study provides detailed theoretical analysis of homonuclear spin-polarized alkali-metal trimers, determining their geometries and binding energies, and compares these with recent experimental data to improve understanding of these molecules.

Contribution

It offers new high-level quantum chemical calculations of alkali-metal trimers' geometries and energies, and discusses their comparison with experimental results.

Findings

Equilibrium geometries for Li3, Na3, K3, Rb3, Cs3 determined.

Comparison with experimental Coulomb explosion data.

Proposals for further theoretical studies to interpret experiments.

Abstract

Homonuclear spin-polarized alkali-metal trimers in their lowest-lying electronic state are investigated theoretically. Their equilibrium geometries and binding energies are determined with the state-of-the-art quantum chemical methods at three levels of approximation. The equilibrium geometries obtained $R_{\rm eq}({\rm Li}_3) = 3.100$ \r{A}, $R_{\rm eq}({\rm Na}_3) = 4.353$ \r{A}, $R_{\rm eq}({\rm K}_3) = 4.996$ \r{A}, $R_{\rm eq}({\rm Rb}_3) = 5.391$ \r{A}, and $R_{\rm eq}({\rm Cs}_3) = 5.730$ \r{A} are compared to the other theoretical results and also with the very recent experimental results obtained through the laser-induced Coulomb explosion. Further theoretical studies are proposed, which could help with better interpretation of the experimental results for the sodium and cesium trimers.