See CrySPY document
https://tomoki-yamashita.github.io/CrySPY_doc/cryspy_utility/
2024 April 16: update extract_struc.py
2023 August 8: upload the example of CHGNET
2023 July 23: update extract_struc.py and pos2pkl.py
2023 July 10: update repeat_cryspy. add example of ASE
2023 March 14: Moved examples and f-fingerprint from CrySPY to CrySPY utility
2022 May 16: update exract_struc.py