title: Role of Many-Body Effects in Describing Low-Lying Excited States of π-Conjugated Chromophores: High-Level Equation-of-Motion Coupled-Cluster Studies of Fused Porphyrin Systems.
abstract: The unusual photophysical properties of the π-conjugated chromophores make them potential building blocks of various molecular devices. In particular, significant narrowing of the HOMO-LUMO gaps can be observed as an effect of functionalization chromophores with polycyclic aromatic hydrocarbons (PAHs). In this paper we present equation-of-motion coupled cluster (EOMCC) calculations for vertical excitation energies of several functionalized forms of porphyrins. The results for free-base porphyrin (FBP) clearly demonstrate significant differences between functionalization of FBP with one- (anthracene) and two-dimensional (coronene) structures. We also compare the EOMCC results with the experimentally available results for anthracene fused zinc-porphyrin. The impact of various types of correlation effects is illustrated on several benchmark models, where the comparison with the experiment is possible. In particular, we demonstrate that for all excited states considered in this paper, all of them being dominated by single excitations, the inclusion of triply excited configurations is crucial for attaining qualitative agreement with experiment. We also demonstrate the parallel performance of the most computationally intensive part of the completely renormalized EOMCCSD(T) approach (CR-EOMCCSD(T)) across 120 000 cores.
authors.affiliation: William R. Wiley Environmental Molecular Sciences Laboratory, Battelle, Pacific Northwest National Laboratory , K8-91, P.O. Box 999, Richland, Washington 99352, United States.|Cray, Incorporated , 380 Jackson St. Suite 210, St. Paul, Minnesota 55101, United States.|High Performance Computing, Pacific Northwest National Laboratory , Richland, Washington 99352, United States.|Computer Science and Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: K
authors.initials: K
authors.lastname: Kowalski
authors.affiliation: William R. Wiley Environmental Molecular Sciences Laboratory, Battelle, Pacific Northwest National Laboratory , K8-91, P.O. Box 999, Richland, Washington 99352, United States.|Cray, Incorporated , 380 Jackson St. Suite 210, St. Paul, Minnesota 55101, United States.|High Performance Computing, Pacific Northwest National Laboratory , Richland, Washington 99352, United States.|Computer Science and Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: R M
authors.initials: RM
authors.lastname: Olson
authors.affiliation: William R. Wiley Environmental Molecular Sciences Laboratory, Battelle, Pacific Northwest National Laboratory , K8-91, P.O. Box 999, Richland, Washington 99352, United States.|Cray, Incorporated , 380 Jackson St. Suite 210, St. Paul, Minnesota 55101, United States.|High Performance Computing, Pacific Northwest National Laboratory , Richland, Washington 99352, United States.|Computer Science and Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: S
authors.initials: S
authors.lastname: Krishnamoorthy
authors.affiliation: William R. Wiley Environmental Molecular Sciences Laboratory, Battelle, Pacific Northwest National Laboratory , K8-91, P.O. Box 999, Richland, Washington 99352, United States.|Cray, Incorporated , 380 Jackson St. Suite 210, St. Paul, Minnesota 55101, United States.|High Performance Computing, Pacific Northwest National Laboratory , Richland, Washington 99352, United States.|Computer Science and Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: V
authors.initials: V
authors.lastname: Tipparaju
authors.affiliation: William R. Wiley Environmental Molecular Sciences Laboratory, Battelle, Pacific Northwest National Laboratory , K8-91, P.O. Box 999, Richland, Washington 99352, United States.|Cray, Incorporated , 380 Jackson St. Suite 210, St. Paul, Minnesota 55101, United States.|High Performance Computing, Pacific Northwest National Laboratory , Richland, Washington 99352, United States.|Computer Science and Mathematics Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
authors.forename: E
authors.initials: E
authors.lastname: Aprà