Frozen-density embedding as an efficient method for modeling solvent effects on molecular properties

PHYS 459

Christoph R. Jacob, jacob@few.vu.nl1, Johannes Neugebauer, Johannes.Neugebauer@phys.chem.ethz,ch2, Evert Jan Baerends, baerends@chem.vu.nl1, and Lucas Visscher, visscher@chem.vu.nl1. (1) Theoretical Chemistry, Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, Netherlands, (2) Laboratory of Physical Chemistry, ETH Zurich, 8093 Zurich, Switzerland
We present the efficient implementation of the orbital-free frozen-density embedding (FDE) scheme for the description of solvent effects on molecular properties. To obtain molecular properties in solution, this scheme is used in combination with a simplified way of constructing the frozen electron density of the solvent environment, e.g., by using a sum-of-molecular-fragments density. In our implementation the embedding potential is evaluated in a way that scales linearly (with a very small prefactor) with the size of the frozen environment and, therefore, allows for investigations on very large systems. This is shown for the absorption spectrum of aminocoumarin C151, where calculations with up to 1500 atoms in the solvent shell were carried out. Furthermore, we have compared the performance of FDE to a purely electrostatic solvent model based on a QM/MM scheme using a polarizable force field. It is found that both solvent models agree for ground-state properties, while there are significant differences in the description of response properties.
 

Poster Session
7:30 PM-10:00 PM, Wednesday, 13 September 2006 Moscone Center -- Hall D, Poster

Division of Physical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006