The objective of our research is to establish new theoretical methods in the study of intermediate size and extended systems. Specifically, the research includes developments of new ab initio theories and their applications. Intermediate means a system that is sufficiently large to have intermediate chemical and physical properties between small molecules and extended systems. An example might be a significant portion of a nanostructural material.
With the help of ever improving computer hardware and new theories, computational chemistry, and electronic structure theory in particular, is evolving into an essential tool in exploring and understanding the nature of chemical systems. At the same time, it is quite clear that conventional electronic structure theories may not be able to keep pace with the growth of demands due to the fact that even in the simplest method, the Hartree-Fock (HF) theory, the amount of computations needed increases roughly as O(N4), where N is the number of basis functions.
In talk, we present our on-going theoretical developments and proposals to overcome the bottlenecks of current quantum mechanical methods, and their applications to extended systems, in which new methods could bring us new chemical insights.