0000000000563843
AUTHOR
Lea Thøgersen
The Dalton quantum chemistry program system
Dalton is a powerful general-purpose program system for the study of molecular electronic structure at the Hartree-Fock, Kohn-Sham, multiconfigurational self-consistent-field, MOller-Plesset, confi ...
Equilibrium Geometry of the Ethynyl (CCH) Radical
The equilibrium geometry of the ethynyl (CCH) radical has been obtained using the results of high-level quantum chemical calculations and the available experimental data. In a purely quantum chemical approach, the best theoretical estimates (1.208 A for r C C and 1.061-1.063 A for r C H ) have been obtained from CCSD-(T), CCSDT, MR-AQCC, and full CI calculations with basis sets up to core-polarized pentuple-zeta quality. In a mixed theoretical-experimental approach, empirical equilibrium geometrical parameters (1.207 A for r C C and 1.069 A for r C H ) have been obtained from a least-squares fit to the experimental rotational constants of four isotopomers of CCH which have been corrected fo…