The expense of a calculation at MP2, CCSD, and CCSD(T) levels of theory nominally scale as N5, N6, and N7 respectively, where N is the number of atoms. Therefore, enabling accurate calculations on large systems including the active sites of Zn and Cd containing enzymes with post-Hartree�Fock methods remains challenging due to the rapid scaling of the computational cost. In this poster we present the development, application, and optimization of EE-MB and EE-MB-CE methods for the calculation of zinc-ligand and cadmium-ligand bond dissociation energies in pentacoordinate and hexacoordinate Zn and Cd complexes, including a model of the catalytic site of the zinc-bearing anthrax toxin lethal factor (LF). We also present a new, simple, and unambiguous fragmentation strategy for use in the EE-MB and EE-MB-CE calculations. Following this strategy, we show that an average absolute error for the EE-3B-CE method for all 53 bond dissociation energies in all ten Zn and Cd complexes is only 0.59 kcal/mol which is only 0.93% of the average absolute bond dissociation energy of 63.29 kcal/mol. Therefore, one could use the EE-3B-CE approximation to obtain accurate results for large systems (for example, systems with large ligands) where full calculations on the whole complex with a reliable method are unaffordable.

Application of electrostatically embedded many-body approximation of the energy (EE-MB) and the correlation energy (EE-MB-CE) methods to zinc and cadmium penta- and hexacoordinate complexes

246th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.