C-1-15

FMO calculations with ABINIT-MP on K-computer
Yoshio Okiyama1

Chiduru Watanabe1

Kaori Fukuzawa1,2

okiyama@iis.u-tokyo.ac.jp

chiduru@iis.u-tokyo.ac.jp

kaori.fukuzawa@mizuho-ir.co.jp

123
4

Shigenori Tanaka3

Yuji Mochizuki1,4

tanaka2@kobe-u.ac.jp

fullmoon@rikkyo.ac.jp

Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku,
Tokyo 153-8505, Japan
Mizuho Information & Research Institute Inc., 2-3 Kanda Nishiki-Cho, Chiyoda-ku,
Tokyo 101-8443, Japan
Graduate School of System informatics, Kobe University, 1-1 Rokkodai, Nada-ku,
Kobe 657-8501, Japan
Faculty of Science, Rikkyo University, 3-34-1 Nishi-ikebukuro, Toshima-ku, Tokyo
171-8501, Japan

Keywords: fragment molecular orbital (FMO) method, many-body expansion, Cholesky decomposition, massively parallel computing, K-computer
The K-computer, one of the fastest peta-scale supercomputers in the world, processes huge amountsof tasks at once with its massive parallelism and have started being utilized for drug discovery primarily
based on the classical mechanical approaches.
On the other hand, fragment molecular orbital (FMO) method proposed by Kitaura et al. in 1999
has revealed the electronic properties of large biomolecular systems quantum-mechanically and has agreat expectation for application to drug discovery. Especially, the four-body corrected FMO method(FMO4) [1], which is implemented to an FMO processing program, ABINIT-MP, enables us to divide
a molecular system more finely with keeping good accuracy and analyze inter-fragment interactions
with higher resolution favorable to the structure-based drug design (SBDD) [2]. While the number oftetrameric combinations of fragments needed for four-body correction voluminously increases as thewhole system size, one can simultaneously complete all the tasks of processing the combinations in amoment by using the K-computer.
The Cholesky decomposition (CD) technique for two-electron repulsion integral approximation [3]is essential to accelerate the second-order Moeller-Plesset perturbation processes in FMO calculations
by keeping the Cholesky basis on memory and executing the DGEMM operations. For saving memory
and further acceleration, we introduce the CD approximation with one-center Cholesky basis (1CCD) [4], which limits the atomic orbital pairs as the Cholesky basis to those on the same atoms. The
computational times in Hartree-Fock processes are also reduced successfully by applying the 1C-CD
approximation.
Details of our trials and applications with ABINIT-MP on the K-computer will be shown in theposter session.
Acknowledgment This research was supported by the grant for “Strategic Programs for InnovativeResearch” Field No. 4: Industrial Innovations from the Ministry of Education, Culture, Sports,
Science, and Technology (MEXT)’s “Development and Use of Advanced, High-Performance, GeneralPurpose Supercomputers Project.”
References[1] Nakano, T., et al., Chemical Physics Letters, 523:128–133, 2012.
[2] Watanabe, C., et al., Journal of Molecular Graphics and Modelling, 41:31–42, 2013.
[3] Okiyama, Y., et al., Chemical Physics Letters, 490:41–45, 2010.
[4] Aquilante, F., et al., Journal of Chemical Physics, 127:114107, 2007.