Calculation of the electron affinity and ¹A<inf>1</inf>-³B<inf>1</inf> T<inf>0</inf> value of methylene using the ab initio MRD CI method for a large AO basis

Abstract

Ab initio CI calculations for CH2 and CH-2 predict 1A1-2B1 and 1A1-3B1 T0 values of 1.01 eV (after applying a 0.20 eV correction based on carbon atom EA results) and 0.50 eV respectively. A reinterpretation of recent photodetachment experiments is suggested which places the corresponding observed findings at 1.05 ± 0.03 and 0.51 ± 0.03 eV respectively, whereby two low-intensity features seen in the spectrum are reassigned as either 3B1-2B1 hot bands or as transitions originating from the 2A1 excited state of the negative ion. © 1978.