title: QM:QM embedding using electronic densities within an ONIOM framework: energies and analytic gradients.
abstract: Accurate calculations of large systems remain a challenge in electronic structure theory. Hybrid energy techniques are a promising family of methods for treating such systems. Expanding on previous developments, we present a QM:QM electronic embedding model whereby the high-level region is polarized by the electron density of the low-level region within an ONIOM framework. A direct Coulomb embedding model as well a more computationally efficient model involving a density fitting expansion are considered. We also develop a generalized theory for the first derivatives of these classes of QM:QM electronic embedding schemes, which requires solution of a single set of self-consistent field response equations. Two initial test cases are presented and discussed.
authors: Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA. hrant@gaussian.com
authors: Hrant P
authors: HP
authors: Hratchian
authors: Aliaksandr V
authors: AV
authors: Krukau
authors: Priya V
authors: PV
authors: Parandekar
authors: Michael J
authors: MJ
authors: Frisch
authors: Krishnan
authors: K
authors: Raghavachari