The structures of c-C4F8 and and the adiabatic electron affinity of c-C4F8

Calculations at the 6311G(dps) level have been used to elucidate the structures of octafluorocyclobutane c-C4F8 and its negative ion c - C 4 F 8 - . With no empirical adjustments, we obtain 0.640 eV for the adiabatic electron affinity of c-C4F8. This may be compared with an experimental value of 0.63 ± 0.05 eV from the FALP method. c-C4F8 has unusual features in that there is an increase in symmetry, D2d to D4h, in going from the neutral molecule to the negative ion, and the singly occupied molecular orbital in the ion has an unexpected nodal structure.