Recent advances in ab initio, density functional theory, and relativistic electronic structure theory

This chapter focuses on development of abinitio multireference-based perturbation theory, exchange and correlation functionals in density functional theory, and molecular theory including relativistic effects. The new developed methodologies in quantum chemistry, particularly the multireference-based perturbation theory for describing chemical reactions and excited states, relativistic molecular theory to treat heavy elements, parameter-free (less) and long-range corrected (LC) exchange and correlation functionals in density functional theory, highly efficient algorithms for calculating molecular integrals over generally contracted Gaussians, etc. UTCHEM is a research product of work to develop new and better theoretical methods in quantum chemistry. Most of the codes have been developed recently by Hirao's group at the University of Tokyo. The basic philosophy behind UTCHEM is to develop methods that allow an accurate and efficient computational chemistry of electronic structure problems for molecular systems in both the ground and excited states. UTCHEM also contains codes for well-developed methods such as MPn, CI, and CC, etc., which are standard in most quantum chemistry programs.