We provide Qsymm as free software under a BSD license. If you have used Qsymm for work that has lead to a scientific publication, please mention the fact that you used it explicitly in the text body.
In addition we ask you to cite the Qsymm paper:
Dániel Varjas, Tómas Ö Rosdahl, and Anton R Akhmerov
Qsymm: algorithmic symmetry finding and symmetric Hamiltonian generation
New J. Phys. 20 093026 (2018)