title: Ab initio calculations of electronically excited states of cyano-substituted polyacetylene cations.
abstract: The transition energies for the lowest energy pi --> pi* electronic excitations are calculated with the complete active space self-consistent field method (CASSCF) and with the complete active space second-order perturbation theory method (CASPT2) for the linear cyano-substituted polyacetylene cations, H-Cn-CN+, n = 4-11, and NC-Cn-CN+, n = 2-10. These systems are models for an important class of interstellar species. We demonstrate the utility of the theoretical calculations in assigning the experimental spectra.
authors.affiliation: Chemistry Department, University of Arizona, Tucson 85721, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Lee
authors.forename: L
authors.initials: L
authors.lastname: Adamowicz
mesh_terms: D000114:Acetylene / Q000031:analogs & derivatives* / Q000737:chemistry*; D055580:Astronomical Phenomena; D001256:Astronomy; D002412:Cations / Q000737:chemistry; D019443:Cosmic Dust / Q000032:analysis*; D008956:Models, Chemical; D011108:Polymers / Q000737:chemistry*; D053279:Polyynes
chemical_list: D002412:Cations; D019443:Cosmic Dust; D011108:Polymers; D053279:Polyynes; D000114:Acetylene