Accuracy in theoretical excited-state dipole moments

PHYS 359

Rollin A. King, rking@bethel.edu, Department of Chemistry, Bethel University, 3900 Bethel Drive PO#107, St. Paul, MN 55112
The excitation energies and dipole moments for the lowest 15 excited states of furan and 19 excited states of pyrrole have been determined via equation-of-motion coupled cluster theory (EOM-CCSD and EOM-CC3) with basis sets as large as aug-cc-pVTZ. The inclusion of triple excitations is shown to uniformly reduce the computed excitation energies by 0.04-0.24 eV with an average reduction of 0.09 eV. Using basis sets larger than DZP++ (double-zeta plus polarization with diffuse functions) changes the EOM-CCSD excitation energies by an average of 0.09 eV, most often in the upward direction. The basis-set effect on the computed dipole moments (average change of 0.27 au) is much larger than the impact of triple excitations (0.08 au). The computed dipole moments are compared to those computed and tabulated by Burcl, Amos, and Handy [Chemical Physics Letters 355 (2002) 8]. For excited-state dipole moments, the asymptotic correction for time-dependent DFT of Tozer and Handy improves the predicted values by 20-40%, and the B97-1 functional outperforms the HCTC functional. However, neither of these functionals predicts dipole moments as accurate as previously reported CASSCF values, and even with the asymptotic correction, the B97-1 dipole moments are in error by an average of 0.6 au.
 

General Posters
7:30 PM-10:00 PM, Wednesday, March 28, 2007 Hyatt Regency Chicago -- Riverside Center, Poster

Division of Physical Chemistry

The 233rd ACS National Meeting, Chicago, IL, March 25-29, 2007