Large-Scale and Highly Accurate Relativistic Quantum-Chemical Scheme:toward Establishment ofTheoretical Foundation for Element Strategy

Abstract

The article discusses a highly efficient and accurate theory for electronic-state calculations of large-scale heavy-element compounds. After overviewing the current relativistic quantum-chemical theories, the authors describe what points should be considered and improved in order to attain the objective. In addition, they have developed an efficient and accurate two-component relativistic scheme, termed local unitary transformation (LUT) scheme based on infinite-order Douglas-Kroll-Hess method. Numerical applications show the effectiveness of the scheme. Furthermore, the extension of the LUT scheme to the divide-and-conquer (DC) method achieves overall linear-scaling computational cost. In particular, the present scheme would realize a paradigm shift from a non-relativistic (NR) framework to a relativistic one in the quantum chemistry field because the scheme gives close results to four-component relativistic ones with NR computational costs.