High Performance Computing
Infrastructure (HPCI)
andSoftware Development
Shinji Tsuneyuki
Department of Physics, The University of Tokyo
ISSP, The University of Tokyo
1

HPCI (High Performance Computing Infrastructure)
High-Performance Computing Infrastructure (HPCI) is a shared computational environment
in Japan. The mission of HPCI is to realize the scientific and technological computing
environment where a wide range of HPC users in Japan can access national HPC resources
efficiently.

Fugaku (2021-)

University/National InstituteSupercomputer
Centers
Laboratory
Computers

HPCI

K Computer(2012.6-2019.8)

Institute for Solid State Physics,
The University of Tokyo
東大・物性研究所
Institute for Molecular Science,
National Inst. Natural Sciences
分子科学研究所
Institute for Materials Research,
Tohoku University
東北大・金属材料研究所

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FLAGSHIP 2020 Project (FY2015-2019)

Development of
Post-K computer “FUGAKU”

Development ofApplication Software

http://www.aics.riken.jp/en/postk/project3

9 priority issues in FLAGSHIP 2020 Project

http://www.aics.riken.jp/fs2020p/en/

4CDMSI (FY2015-2019)

Creation of new functional
Devices and high-performance
Materials to
Support next-generation
Industries
The Institute for Solid State Physics,
the University of Tokyo

http://www.aics.riken.jp/fs2020p/en/

and 9 other institutes:

Institute for Materials Research (Tohoku Univ.), Institute for Molecular Science,
University of Tsukuba, Osaka University, Nagoya University, Nagoya Institute ofTechnology, Yokohama National University, Tokyo University of Science,
National Institute of Advanced Industrial Science and Technology

5Sub-issues in CDMSI (FY2015-2019)
Sub-issue G: Fundamental methods formaterials science simulation

Methods

DeviceSub-issue A: New-functionality and highperformance semiconductor
devices
Sub-issue B: Unified photonic-electronic devices
Sub-issue C: Superconductors and newfunctional devices and materials

Materials
Sub-issue D: High performance permanent
magnets and magnetic materials
Sub-issue E: Advanced structural materials
Sub-issue F: Next-generation functional chemicalsubstance6

A portal site for materials sciencesimulation

4300 users, >16000 pageview / month (FY2019)2116 users, 11267 pageview / month (FY2018)7

OpenMX

http://www.openmx-square.org

Ø A software package for electronic-structure calculation
based on Density Functional Theory (DFT)Ø Norm-conserving pseudopotentials
Ø Variationally optimized numerical atomic basis functions
Ø Besides basic functions, the package is equipped with
• O(N) method• Calculation of Magnetic anisotropy energy (MAE),• Exchange coupling parameters,• Z2 & Chern topological invariant,• Core level calculations for XPS• Interface with BoltzTrap
and many other functions

Main Contributor:
Taisuke Ozaki(ISSP, U. Tokyo)

Magnetic Materials (ESICMM)
Structural Materials (ESISM)
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Appendix

New features in OpenMX Ver. 3.9

Taisuke Ozaki (ISSP, Univ. of Tokyo)
Dec. 3, 2019

OpenMX Open source package for Material eXplorer•Software package for density functional calculations of molecules and bulks•

Norm-conserving pseudopotentials (PPs)•

Variationally optimized numerical atomic basis functions

Basic functionalities

Extensions•

SCF calc. by LDA, GGA, DFT+U•

O(N) and low-order scaling diagonalization•

Total energy and forces on atoms•

Non-collinear DFT for non-collinear magnetism•

Band dispersion and density of states•

Spin-orbit coupling included self-consistently•

Geometry optimization by BFGS, RF, EF•

Electronic transport by non-equilibrium Green function•

Charge analysis by Mullken, Voronoi, ESP•

Electronic polarization by the Berry phase formalism•

Molecular dynamics with NEV and NVT ensembles•

Maximally localized Wannier functions•

Charge doping•

Effective screening medium method for biased system•

Fermi surface•

Reaction path search by the NEB method•

Analysis of charge, spin, potentials by cube files•

Band unfolding method•

Database of optimized PPs and basis funcitons•

STM image by the Tersoff-Hamann method

•

etc.

New features in OpenMX Ver. 3.9
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Database 2019 of PAO and VPS (Ozaki)
Database 2019 of PAO and VPS for core level excitation (Ozaki)
Core level calculations for XPS (Ozaki)
O(N) DC-LNO method (Ozaki)
Calculations of gaseous charged systems (Ozaki)
Complex dielectric function & optical conductivity tensors (YTL)
Spin texture for Rashba effect (Kotaka, Yamaguchi, Ishii)
Generalized Bloch theorem for spin spiral (Prayitno, Ishii)
Z2 & Chern topological invariant (Sawahata, Ishii)
Improvement of polB (Yamaguchi)
Second variational scheme of SOI (Po-Hao Chang)
Efficient implementation of jij (Terasawa)
Optimization of enthalpy (Ozaki)
New DFT+U functionals (Ryee&Han)
Mixing methods of DIISV (Ozaki)
ELPA1/ELPA2 (Duy and Ozaki)
OpenMX engine by MPI_spawn (Ozaki)
Jx (Yoon, Kim, Sim, Han)
Interface with FermiSurfer (Kawamura)Interface with BoltzTrap (Miyata)Interface with ASE (Yu)Second variational scheme for evaluation of magnetic
anisotropy energy (MAE) supported by P.-H. Chang and Ozaki
A second variational method is supported to calculate band structures modified with
spin-orbit coupling (SOI) and magnetic anisotropy energy (MAE).

Second variationalscheme
L10-FePt• First, the SCF calculationis performed by thecollinear DFT• Second, with the SCF
charge the one-shotdiagonalization isperformed with SOI.
• The total energy isevaluated by the Harrisfunctional.
12Efficient calculations of exchange coupling parameterssupported by Terasawa, Ozaki, and Gohda
A post-processing code 'jx' to calculate exchange coupling parameters Jij has been largely
improved so that the individual Jij in bulks can be calculated efficiently using a contour
integration method.

Currie temperature

13A Terasawa, M Matsumoto, T Ozaki, and Y Gohda, J. Phys. Soc. Jpn. 88, 114706 (2019).

Chern number, Berry curvature, and Z2 invariantsupported by Sawahata and Ishii
In OpenMX Ver. 3.9, a post-processing code 'calB' is supported to calculate theChern number and Berry curvature of bands using overlap matrix elements between
Kohn-Sham orbitals at neighboring k-points by the Fukui-Hatsugai-Suzuki method.
The Chern number is a topological invariant being an integer number, whichcharacterizes the topology of bands for any materials. We also release another postprocessing code 'Z2FH' to calculate the Z2 topological invariant using the Berryphase by the Fukui-Hatsugai method.
An example for the calculation ofinteger-valued field Bi2Se3

Berry curvature for bands of graphene

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H. Sawahata, N. Yamaguchi, H. Kotaka, and F. Ishii, Jpn. J. Appl. Phys. 57, 030309 (2018).

Absolute binding energies of core levels
XPS core level energies supported by Ozaki
A general method has been supported to calculate absolute binding energies of core levels inmetals and insulators, based on a penalty functional and an exact Coulomb cutoff method in theframework of density functional theory. With the method one can treat multiple splittings dueto chemical shift, spin-orbit coupling, and exchange interaction on equal footing.

Eb = Ef(0) ( N - 1) - Ei(0) ( N ) + µ 0
Penalty functional

Ef = EDFT + Ep
Exact Coulomb cutoff method

Mean absolute error: 0.4 eV, Mean relative error: 0.16 %T. Ozaki and C.-C. Lee, Phys. Rev. Lett. 118, 026401 (2017)15

Interface with BoltzTrap supported by Miyata
OpenMX is interfaced with BoltzTraP which calculates electron transport coefficients
based on the Boltzmann theory from the wave number dependence of the energyeigenvalues in the Kohn-Sham equation. The interface with BoltzTraP enables us tocalculate physical properties such as the Seebeck coefficient, electrical conductivity,electronic thermal conductivity, and the Hall coefficient. The functionality is compatible
with not only the collinear calculations, but also the non-collinear calculations.
M. Miyata et al., Journal of Electronic Materials 47, 3254 (2017).

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