A MRCC study of the isomerisation of cyclopropane

0484086 - ÚFCH JH 2018 RIV GB eng J - Journal Article
Lang, Jakub - Švaňa, Matěj - Demel, Ondřej - Brabec, Jiří - Kedžuch, S. - Noga, J. - Kowalski, K. - Pittner, Jiří
A MRCC study of the isomerisation of cyclopropane.
Molecular Physics. Roč. 115, č. 21-22 (2017), s. 2743-2754. ISSN 0026-8976. E-ISSN 1362-3028
R&D Projects: GA ČR GJ15-00058Y; GA ČR GA16-12052S
Grant - others:Ga MŠk(CZ) LM2015070
Institutional support: RVO:61388955
Keywords : Coupled cluster * LPNO, trimethylene * universal state selective * multireference
OECD category: Physical chemistry
Impact factor: 1.704, year: 2017

Mukherjee's and Brillouin-Wigner multi-reference coupled clustermethods with universal state selective (USS) corrections were used to study the isomerisation of cyclopropane to propene through a trimethylene/propylidene diradicals. Main aim was to obtain high quality ab-initio data using advanced methods that treat both static and dynamic correlation in the involved species, however, we also report implementation of the diagonal USS correction in the LPNO-MRCC code and its performance assessment. The MkCCSD(T)/cc-pV5Z lower bound of interaction energy of cyclopropane isomerisation via trimethylene is 65.6 kcal/mol (59.9 kcal/mol with ZPVE correction), in a good agreement with experimental values in the range 60-65 kcal/mol. The MkCCSD(T)/cc-pV5Z adiabatic singlettriplet gap in trimethylene is 0.6 kcal/mol, slightly higher than previous CASPT2 result 0.7 kcal/mol by Skancke et al.
Permanent Link: http://hdl.handle.net/11104/0279280