Electronic excitation spectra of furan and pyrrole: Revisited by the symmetry adapted cluster–configuration interaction method

• DOI: 10.1063/1.1316034
• Publication Date: 2002-07-26T12:41:43Z
• Authors: Jian Wan; Jaroslaw Meller; Masahiko Hada; Masahiro Ehara; Hiroshi Nakatsuji
• Keywords: Furan; Multireference configuration interaction; Pyrrole; Coupled cluster

Electronic excitation spectra of furan and pyrrole are reinvestigated by the symmetry-adapted cluster configuration-interaction method. The 47 46 lowest singlet triplet electronic states computed for pyrrole, respectively. Two series (1a2 2b1) low-lying Rydberg valence π–π* excited strongly influence each other in both pyrrole. present calculations give detailed satisfactory theoretical assignments vacuum ultraviolet electron energy-loss two molecules. similarities differences excitations between discussed detail. accuracy recent studies, i.e., complete active space second-order perturbation, multireference Møller–Plesset algebraic-diagrammatic construction, double configuration interaction, CC3, compared.