Effective Fragment Potentials for Microsolvated Excited and Anionic States

Cate S Anstöter, Salsabil Abou-Hatab, Mushir Thodika, Spiridoula Matsika

Research output: Contribution to journalArticlepeer-review


The effective fragment potential (EFP) approach is a sophisticated hybrid approach that allows the inclusion of solvation effects when describing properties and reactivity in the condensed phase, without using empirical parameters. This work examines the performance of the EFP method when describing microsolvation in electronically excited states of neutrals and anions. The examples selected include both localized valence states, as well as diffuse nonvalence states, which represent greater challenges to conventional electronic structure methods. The equation-of-motion coupled cluster with singles and doubles (EOM-XX-CCSD) methodology has been used to provide the quantum chemical description of both the full microsolvated clusters, and the chromophoric moiety in mixed quantum/EFP calculations. We find that, when averaging over multiple configurations of microsolvated clusters, the differences between QM/EFP and full quantum results are minimal, although individual configurations often have larger errors. As expected, diffuse states have somewhat larger errors, although not significantly so. The close proximity of states leading to mixing can make QM/EFP less accurate because a change of ordering of states can occur. Other properties, such as photoelectron images and lifetimes of metastable states, are very well described for the monohydrated clusters investigated.

Original languageEnglish
Pages (from-to)8508-8518
Number of pages11
JournalJournal of Physical Chemistry A
Issue number45
Early online date3 Nov 2022
Publication statusPublished - 17 Nov 2022

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