UTChem - A Program for ab initio Quantum Chemistry

Present molecular quantum theory is highly sophisticated, and has evolved dramatically. Software forms a basis for computational chemistry. However, it is not an easy task for an individual/group to develop a comprehensive new program package in ab initio quantum chemistry from scratch. Several years ago, we decided to accept this challenge. In view of the availability of such good programs as Gaussian, Gamess, Molcas, NWChem, etc., one may question the relevance of a new program package. We have three arguments for our project. (1) First, we believe that healthy competition is very important in science. (2) Second, we can have a good harvest by doing research using other programs, but it is an abortive flower. We could not make a true breakthrough if we were circumscribed by current software limitations. (3) Third, in spite of the excellent performance of other programs, there are important and powerful methods that others cannot yet handle. We have developed new 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) exchange and correlation functionals in DFT, highly efficient algorithms for calculating molecular integrals over generally contracted Gaussians, etc. UTChem is a research product of our 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, CC, etc., which are standard in most quantum chemistry programs. We are aiming ultimately at better performance than other programs. UTChem will soon be ready for distribution. Here you will be able to see the features of UTChem. UTChem contains a large number of improvements and some interesting new features, which others cannot match.