Massively parallel computing in the field of theoretical and computational molecular science becomes more important year by year to utilize massively parallel supercomputers to perform the first-principle electronic structure calculations on large-size and complicated molecular systems. Our research team has been developed the novel molecular science software NTChem  for the massively parallel computing of electronic structures on the petascale supercomputer such as the K computer. NTChem involves the novel development of theory and algorithm, which make possible through the collaborative use of the K computer across the fields of computational science and computer science. In this talk, I introduce my works about the development of massively parallel algorithms and its implementations into NTChem. We present the overview of the massively parallel algorithm and its implementation of (1) the Hartree-Fock and density functional theory (DFT) self-consistent field calculations , (2) the time-dependent DFT excited-state calculation , and (3) the resolution of identity second-order Møller–Plesset perturbation (RI-MP2) calculations for energy [3, 4] and energy gradient, respectively.
 Nakajima, T.; Katouda, M.; Kamiya, M.; Nakatsuka, Y. Int. J. Quantum Chem. 2015, 115, 349–359. doi: 10.1002/qua.24860.
 Katouda, M.; Nakajima, T. J. Chem. Theory Comput. 2013, 9, 5373–5380. doi: 10.1021/ct400795v.
 Katouda, M.; Nakajima, T.; Nagase S. Proceedings of JSST 2012, 2012, 338–343.