PROJECTS

Development and application of explicitly-correlated coupled-cluster methods for nonlinear optical properties

PRINCIPAL INVESTIGATOR

TOGETHER WITH

Prof. Dr. Willem Maarten Klopper Universität Karlsruhe Physikalische Chemie Engesserstraße 15 D-76131 Karlsruhe +49-721-608-7263 +49-721-608-3319 klopper@chem-bio.uni-karlsruhe.de

ABSTRACT

Today, coupled-cluster response theory is an established method for the calculation (from first principles) of electronically excited states and linear and nonlinear optical properties. For frequency-dependent (magneto-)optical properties, coupled-cluster response models are the only generally applicable methods that yield an accuracy of a few percent for many-electron systems. However, a serious drawback of coupled-cluster calculations is the slow convergence of the accuracy of the calculated properties with respect to the one-electron basis set. Large basis sets are therefore needed. Fortunately, the convergence can be improved considerably by combining the coupled-cluster (CC) theory with the R12 Ansatz to obtain explicitly-correlated CC-R12 methods. It is the goal of the present project to develop and implement an explicitly-correlated CC-R12 response theory, which will open ways to compute frequency-dependent first and second hyperpolarizabilities and other magneto-optical properties for molecules much larger than those that could be studied before (since basis sets can be kept small with the R12 Ansatz) and with much higher accuracy (close to experimental).