title: Evaluation of incremental correlation energies for open-shell systems: application to the intermediates of the 4-exo cyclization, arduengo carbenes and an anionic water cluster.
abstract: A fully automated procedure for incremental closed-shell CCSD calculations has been extended to open-shell cases tractable with the restricted open-shell CCSD method. It is demonstrated that for monoradical intermediates of the 4-exo cyclization, the triplet state of Arduengo carbenes as well as for water cluster anions chemical accuracy can be reached with respect to the error introduced by the local correlation treatment. Finally, it is shown that the computationally less demanding evaluation of higher-order increments in a smaller basis set does not lead to significant errors.
authors: Institute for Theoretical Chemistry, University of Cologne, Greinstrasse 4, 50939 Cologne, Germany.
authors: Joachim
authors: J
authors: Friedrich
authors: Michael
authors: M
authors: Hanrath
authors: Michael
authors: M
authors: Dolg
mesh_terms: D000838:Anions / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry*; D003198:Computer Simulation; D003500:Cyclization; D004583:Electrons; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D008956:Models, Chemical; D011789:Quantum Theory; D014867:Water / Q000737:chemistry*
chemical_list: D000838:Anions; D002264:Carboxylic Acids; D014867:Water; C030011:carbene; D008697:Methane