A Mountaineering Strategy to Excited States: Highly Accurate Reference Energies and Benchmarks

Pierre-Francois Loos (1) , Anthony Scemama (1) , Aymeric Blondel (2) , Yann Garniron (1) , Michel Caffarel (1) , Denis Jacquemin (3)

1 GMO - Groupe THEO (LCPQ)
2 CEISAM - Chimie Et Interdisciplinarité : Synthèse, Analyse, Modélisation
3 UN - Université de Nantes

Striving to define very accurate vertical transition energies, we perform both high-level coupled cluster (CC) calculations (up to CCSDTQP) and selected configuration interaction (sCI) calculations (up to several millions of determinants) for 18 small compounds (water, hydrogen sulfide, ammonia, hydrogen chloride, dinitrogen, carbon monoxide, acetylene, ethylene, formaldehyde, methanimine, thioformaldehyde, acetalde-hyde, cyclopropene, diazomethane, formamide, ketene, nitrosomethane and the smallest streptocyanine). By systematically increasing the order of the CC expansion, the number of determinants in the CI expansion as well as the size of the one-electron basis set, we have been able to reach near full CI (FCI) quality transition energies. These calculations are carried out on CC3/aug-cc-pVTZ geometries, using a series of increasingly large atomic basis sets systematically including diffuse functions. In this way, we define a list of 110 transition energies for states of various characters

Domaines: Chimie théorique et/ou physique

Pierre-Francois Loos, Anthony Scemama, Aymeric Blondel, Yann Garniron, Michel Caffarel, et al.. A Mountaineering Strategy to Excited States: Highly Accurate Reference Energies and Benchmarks. Journal of Chemical Theory and Computation, 2018, 14 (8), pp.4360 - 4379. ⟨10.1021/acs.jctc.8b00406⟩. ⟨hal-01858532⟩