Accurate Treatment of Strong Electron Correlation in Relativistic Systems

点击翻译按钮获取中文摘要

Sandeep Sharma at the University of Colorado, Boulder is supported by an award from the Chemical Theory, Models and Computational Methods (CTMC) Program in the Chemistry Division to develop high accuracy theoretical methods to predict the properties of transition metal-containing systems, which have critically important technological impacts. Their applications range from catalyzing slow chemical reactions to exhibiting unusual magnetic properties that can used for quantum computing. Despite the technological importance of transition metals, theoretical methods to calculate their properties are much less developed than for organic molecules, where high-accuracy calculations can be performed that rival the accuracy of experiments. This shortcoming can be traced to the intricate interplay between correlated electronic motion and the impacts of relativity, both of which are much more important for transition metals than for organic molecules. Dr. Sharma is working to fill this void by developing a suite of methods to treat metal-containing systems. Predictive, accurate calculations on transition metal systems using these methods can direct experimental efforts in designing efficient and cheap biomimetic catalysts as well help design the next generation of systems for quantum computing. Dr. Sharma is also developing a course to improve the mathematical skills of undergraduate chemists, which is a critical need for young chemists.Dr. Sharma is developing ab initio methods that can reliably be used for transition metal-containing relativistic systems, that also display strong electron correlation. In the last two decades, impressive advances have been made by largely independent communities toward the development of algorithms to treat strong electron correlation and large relativistic effects. However, treating them simultaneously on an equal footing remains a formidable challenge. A major goal of Dr. Sharma's research is the fruitful cross-fertilization of the latest ideas in the two fields in order to develop algorithms that allow the treatment of strongly correlated relativistic systems. More specifically, he is developing methods that: (i) Calculate the ground and low-lying excited states of the fully relativistic four-component Dirac-Coulomb-Breit Hamiltonian for small benchmark systems containing heavy atoms, that are inaccessible by exact diagonalization, to near-exact accuracy. (ii) Implement near-exact diagonalization as an active space method to obtain a quantitatively accurate method for treating large systems of interest in biology and material science. (iii) Employ analytic response theory to calculate fully ab initio spin Hamiltonian parameters in order to predict parameters that are widely used in experiments and theoretical treatments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.