ISOSUBGROUP

Version History

Aug 2023: Version 1.6.2 (1) Resolved a problem that prevented order parameters of ZA-point irreps of certain primitive cubic space groups (195 P23, 198 P2_13, 200 Pm-3, 201 Pn-3, 205 Pa-3). (2) Corrected error in the routine that selects the default domain of an order parameter, which should generally be the simplest-looking OPD. (3) Minor bug fixes.

Jan 2022: Version 1.6.1. Implemented Kovalev IR symbols for all IRs.

Jan 2022: Version 1.6. Implemented UNI (unified) symbols for magnetic space groups and superspace groups.

Sep 2021: Version 1.5 Changed the default domain for many isotropy subgroups involving irreps at special k points.

Jun 2021: Version 1.4.1 Changed the way that incommensurate k vectors are represented internally; this extensive revision should be invisible to users.

Jan 2021: Version 1.4.0 (1) Major modification to the code that enumerates the unique ISGs for multi-k incommensurate distortions. Our published method does not consider cases for which the active arms of an incommensurate k-star differ by a rational k-vector in the parent setting. This weakness has now been rectified. (2) Major modification of the code that computes the secondary order parameters for multi-k incommensurate distortions. We previously failed to consider cases for which the primary and secondary k-vectors differ by a rational k vector.

May 2019: Version 1.3.0 For incommensurate subgroups, a nicer selection of the active k-vectors from amongst equivalent arms of the star of k has been implemented. For incommensurate magnetic subgroups, the magnetic-super-space-group numbers have now been completed following an exhaustive enumeration of the possible groups. This replaces the "?" symbol at the end with an integer.

Oct 2017: Version 1.2.0 Added capability to input desired OPD.

Aug 2016: Version 1.1.0 Updated the code for computing isotropy subgroups at incommensurate k vectors to match that of ISODISTORT version 6.3.0.

June 2016: Version 1.0.0 ISOSUBGROUP first appeared in the ISOTROPY software suite.