Campus Units

Chemistry, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

6-2010

Journal or Book Title

Journal of Physical Chemistry A

Volume

114

Issue

25

First Page

6742

Last Page

6750

DOI

10.1021/jp101780r

Abstract

The simplest variational method for treating electronic excited states, configuration interaction with single excitations (CIS), has been interfaced with the effective fragment potential (EFP) method to provide an effective and computationally efficient approach for studying the qualitative effects of solvents on the electronic spectra of molecules. Three different approaches for interfacing a non-self-consistent field (SCF) excited-state quantum mechanics (QM) method and the EFP method are discussed. The most sophisticated and complex approach (termed fully self consistent) calculates the excited-state electron density with fully self-consistent accounting for the polarization (induction) energy of effective fragments. The simplest approach (method 1) includes a strategy that indirectly adds the EFP perturbation to the CIS wave function and energy via modified Hartree−Fock molecular orbitals, so that there is no direct EFP interaction with the excited-state density. An intermediate approach (method 2) accomplishes the latter in a noniterative perturbative manner. Theoretical descriptions of the three approaches are presented, and test results of solvent-induced shifts using methods 1 and 2 are compared with fully ab initio values. These comparisons illustrate that, at least for the test cases examined here, modification of the ground-state Hartree−Fock orbitals is the largest and most important factor in the calculated solvent-induced shifts. Method 1 is then employed to study the aqueous solvation of coumarin 151 and compared with experimental measurements.

Comments

Reprinted (adapted) with permission from Journal of Physical Chemistry a 114 (2010): 6742, doi:10.1021/jp101780r. Copyright 2010 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

Included in

Chemistry Commons

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