Spglib is a C library for finding and handling crystal symmetries.

Version 1.7.2 has a critical bug and so removed from the download site. Some information is written in ChangeLog and more detais may be found in the source code history at github repository.


  • Find symmetry operations
  • Identify space-group type
  • Wyckoff position assignment
  • Refine crystal structure
  • Search irreducible k-points
  • Find a primitive cell


  • Space-group type finding algorithm: R. W. Grosse-Kunstleve, Acta Cryst., A55, 383-395 (1999)
  • Crystal refinement algorithm: R. W. Grosse-Kunstleve and P. D. Adams, Acta Cryst., A58, 60-65 (2002)


  1. Download spglib.

  2. Unzip, configure, and make:

    % tar xvfz spglib-1.6.tar.gz
    % cd spglib-1.6
    % ./configure
    % make
  3. Copy the libraries where you want using OpenMP. The libraries may be in src/.libs if you don’t make install,


Bottle neck of symmetry operation search may be eased using the OpenMP threading. In the case of gcc (> 4.2), set the following environment variables before running configure script:

% export LIBS='-lgomp'
% export CFLAGS='-fopenmp'

Overhead of threading is relatively large when the number of atoms is small. Therefore the threading is activated when the number of atoms >= 1000.


  1. Include spglib.h
  2. Link libsymspg.a or libsymspg.so
  3. Examples are shown in example.c.


A few examples are stored in example directory. The fortran interface


The ruby code symPoscar.rb in test directory reads a VASP POSCAR formatted file and finds the space-group type. The -l option refines a slightly distorted structure within tolerance spacified with the -s option. The -o option gives the symmetry operations of the input structure.

ruby symPoscar.rb POSCAR -s 0.1 -o -l

How to compile is found in the README file.

Python extension

Python extension for ASE is prepared in the python/ase directory. See http://spglib.sourceforge.net/pyspglibForASE/

Fortran interface

Fortran interface spglib_f08.f90 is found in example directory. This fortran interface is the contribution from Dimitar Pashov. spglib_f.c is obsolete and is not recommended to use.

Mailing list

For questions, bug reports, and comments, please visit following mailing list:


For more information


Spglib project acknowledges Yusuke Seto for the Crystallographic database and Dimitar Pashov for the fortran interface.