Ab initio calculations on porphin

Abstract

Ab initio SCF calculations are reported for the porphin molecule. The positions of the central protons have been optimized, and the equilibrium geometry is found to be a linear NH ⃛ HN arrangement. The NH vibrational frequencies have been computed and are compared to experimentally measured quantities. Several low ionized states have also been studied in separate spin‐restricted SCF calculations. The lowest state is found to have B_1u symmetry with an ionization potential of 8.0 eV.