Michal Novotný a František Karlický publikovali nový článek!

Ab initio investigation of excited states and absorption spectra of small mercury clusters (Hg_2–5)

Odkaz zde: https://doi.org/10.1063/5.0351354

Abstrakt:

We report a systematic ab initio investigation of the excited states and absorption spectra of small mercury clusters (Hg_2–5). Benchmarking multi-reference configuration interaction (MR-CISD) and equation-of-motion coupled-cluster (EOM-CCSD) methods shows that EOM-CCSD/aug-cc-PVTZ-PP reproduces atomic excitation energies within ±500 cm⁻¹ of experiment, whereas MR-CISD deviates by about ±1100 cm⁻¹. For the mercury dimer, EOM-CCSD potential energy curves yield absorption bands in excellent agreement with experimental transitions, while asymptotic excitation energies closely match atomic references. Extending this methodology, we present the first systematic ab initio study of absorption spectra of Hg₃, Hg₄, and Hg₅, which display broad bands in the range of 37 000–60 000 cm⁻¹. The consistent agreement with experimental benchmarks and diagnostics confirming single-reference character validates EOM-CCSD as a robust approach for describing excited states and optical spectra of mercury clusters.