title: A correlated ab initio study of linear carbon-chain radicals CnH (n = 2-7).
abstract: Linear carbon-chain radicals CnH for n = 2-7 have been studied with correlation consistent valence and core-valence basis sets and the coupled cluster method RCCSD(T). Equilibrium structures, rotational constants, and dipole moments are reported and compared with available experimental data. The ground state of the even-n series changes from  2 sigma+ to 2 pi as the chain is extended. For C4H, the 2 sigma+ state was found to lie only 72 cm-1 below the 2 pi state in the estimated complete basis set limit for valence correlation. The C2H- and C3H- anions have also been characterized.
authors.affiliation: Molecular Research Institute, Palto Alto, CA 94304, USA. woon@hecla.molres.org
authors.forename: D E
authors.initials: DE
authors.lastname: Woon
mesh_terms: D055580:Astronomical Phenomena; D001256:Astronomy; D002627:Chemistry, Physical / Q000379:methods*; D003198:Computer Simulation; D006838:Hydrocarbons / Q000737:chemistry*; D006860:Hydrogen Bonding; D008956:Models, Chemical
chemical_list: D006838:Hydrocarbons