ELECTRON-AFFINITIES OF SMALL LINEAR CARBON CLUSTERS - COUPLED CLUSTER CALCULATIONS WITH 1ST-ORDER CORRELATION ORBITALS

Electron affinities of the C3, C4, C5, and C6 linear clusters are theoretically determined using an ab initio procedure which combines the first-order correlation orbital method and the coupled cluster method. The theoretical values 1.58, 3.41, 2.43, and 3.69 e.V. for C3, C4, C5, and C6, respectively, are systematically lower than the experimental estimates of Smalley et al. [Chem. Phys. Lett. 144, 431 (1988)] (1.95, 3.70, 2.80, and 4.10 e.V.); however, the trends corresponding to the odd-even numbered chain alternation and to the increase of the size of the cluster are very similar.