title: Oscillator Strengths in ONIOM Excited State Calculations.
abstract: We compute oscillator strengths with the ONIOM (Our own N-layer Integrated molecular Orbital molecular Mechanics) hybrid method between ground and valence excited states and compare the results with the high level of theory equation of motion coupled cluster singles and doubles (EOM-CCSD). This work follows our previous studies in which we validated the ability of ONIOM to compute accurate transition energies compared to EOM-CCSD. We test various levels of theory and molecular systems, as well as the effect of the link atom bond length. Our results show that oscillator strengths can be accurately computed with ONIOM, provided that a sensible choice of the partitioning and of the low level method is made. Being able to calculate both the transition energy and the oscillator strength, ONIOM represents a promising approach to completely characterize valence excited states of molecules that are too large to be studied with a conventional high-accuracy method.
authors.affiliation: Gaussian, Inc., 340 Quinnipiac St., Bldg. 40, Wallingford, Connecticut 06492, United States, and Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States.
authors.forename: Marco
authors.initials: M
authors.lastname: Caricato
authors.affiliation: Gaussian, Inc., 340 Quinnipiac St., Bldg. 40, Wallingford, Connecticut 06492, United States, and Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States.
authors.forename: Thom
authors.initials: T
authors.lastname: Vreven
authors.affiliation: Gaussian, Inc., 340 Quinnipiac St., Bldg. 40, Wallingford, Connecticut 06492, United States, and Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States.
authors.forename: Gary W
authors.initials: GW
authors.lastname: Trucks
authors.affiliation: Gaussian, Inc., 340 Quinnipiac St., Bldg. 40, Wallingford, Connecticut 06492, United States, and Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Frisch