TY - JOUR
T1 - The ionization potentials of F2
T2 - A comparison of multiconfigurational electron propagator (MCEP) with other large scale methods using the same basis set
AU - Golab, Joseph T.
AU - Thies, Brenda S.
AU - Yeager, Danny L.
AU - Nichols, Jeffrey A.
PY - 1985
Y1 - 1985
N2 - The multiconfigurational electron propagator technique (MCEP) gives reliable vertical ionization potentials (I.P.s) and electron affinities (E.A.s) for atoms and molecules, including open-shell and highly correlated systems. Shake-up and inner-valence I.P.s can be accurately obtained and characterized. In contrast, perturbative-type Green's function (PTGF) approaches are useful for closed-shell systems with relatively little correlation. Perturbative-type Green's functions cannot consistently reliably predict shake-up and inner-valence I.P.s. We have applied the MCEP method to F2 at 2.68 a.u. using 〈4s3p1d〉 and 〈5s4p2d〉 basis sets. In F 2, the complete active space of all valence orbitals is small. Hence, reliable MCEP results should be obtained for all valence ionization processes. In addition, comparison calculations are given using other large scale techniques, i.e., ΔSCF, ΔMCSCF, PTGF, and Δ multireference CI using the same basis sets. The photoelectron spectrum of F2 below 30 eV is not well characterized experimentally except for the three lowest principal peaks, and apparently no reliable spectra have been reported for higher energies. We report and characterize several I.P.s in F2 0-60 eV, including several I.P.s that have not as yet been observed experimentally.
AB - The multiconfigurational electron propagator technique (MCEP) gives reliable vertical ionization potentials (I.P.s) and electron affinities (E.A.s) for atoms and molecules, including open-shell and highly correlated systems. Shake-up and inner-valence I.P.s can be accurately obtained and characterized. In contrast, perturbative-type Green's function (PTGF) approaches are useful for closed-shell systems with relatively little correlation. Perturbative-type Green's functions cannot consistently reliably predict shake-up and inner-valence I.P.s. We have applied the MCEP method to F2 at 2.68 a.u. using 〈4s3p1d〉 and 〈5s4p2d〉 basis sets. In F 2, the complete active space of all valence orbitals is small. Hence, reliable MCEP results should be obtained for all valence ionization processes. In addition, comparison calculations are given using other large scale techniques, i.e., ΔSCF, ΔMCSCF, PTGF, and Δ multireference CI using the same basis sets. The photoelectron spectrum of F2 below 30 eV is not well characterized experimentally except for the three lowest principal peaks, and apparently no reliable spectra have been reported for higher energies. We report and characterize several I.P.s in F2 0-60 eV, including several I.P.s that have not as yet been observed experimentally.
UR - http://www.scopus.com/inward/record.url?scp=0001608455&partnerID=8YFLogxK
U2 - 10.1063/1.450182
DO - 10.1063/1.450182
M3 - Article
AN - SCOPUS:0001608455
SN - 0021-9606
VL - 84
SP - 284
EP - 299
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 1
ER -