PROJECTS

PRINCIPAL INVESTIGATOR

Prof. Dr. Hans-Joachim Werner Universität Stuttgart Theoretische Chemie Pfaffenwaldring 55 70569 Stuttgart (+49)711/685-4401 (+49)711/685-4442 werner@theochem.uni-stuttgart.de

PROJECT RESEARCH ASSISTANT

ABSTRACT

The aim of the current project is to improve the basis set convergence in local correlation methods by including r₁₂-dependent correlation factors. The methods should be applicable to molecules with 50-100 atoms and yield accurate results with medium-size basis sets. Initially, the theory will be based on local Møller-Plesset perturbation theory (LMP2), but it is planed to extend this later to local coupled-cluster methods. In addition to the linear r₁₂ operator used in the R12-method of Kutzelnigg and Klopper, alternative correlation factors, which are better suited for calculations on large molecules, will be implemented and tested for LMP2. Following recent work of Manby, fixed contractions of Gaussian Geminals will be used and optimized for this purpose. The computation of 3- and 4-electron integrals will be avoided using RI-approximations as in R12-theory, and the 2-electron integrals will be evaluated using efficient density fitting approximations. The accuracy the new methods will be systematically investigated by computing reaction energies. If possible, the new methods will also be applied for QM/MM studies of catalytic reactions and to model the interaction of metallodrugs with DNA.