  In this research, we have been constructing a large database of molecules by
{\it ab initio} calculations. Currently, we have over 1.53 million entries of
6-31G* B3LYP optimized geometries and ten excited states by 6-31+G* TDDFT
calculations. To calculate molecules, we only refer the InChI (International
Chemical Identifier) representation of chemical formula by the International
Union of Pure and Applied Chemistry (IUPAC), thus, no reference to experimental
data. These results are open to public at http://pubchemqc.riken.jp/. The
molecular data have been taken from the PubChem Project
(http://pubchem.ncbi.nlm.nih.gov/) which is one of the largest in the world
(approximately 63 million molecules are listed) and free (public domain)
database. Our final goal is, using these data, to develop a molecular search
engine or molecular expert system to find molecules which have desired
properties.
