Note that the file NCDist.h is a third-party unit cell distance calculation program,
writen under LGLPL, the license for which is attached. The references for this program are:

@article{andrews2014geometry,
title={The geometry of Niggli reduction: BGAOL-embedding Niggli reduction and analysis of boundaries},
author={Andrews, Lawrence C and Bernstein, H. J.},
journal={Journal of Applied Crystallography},
volume={47},
number={1},
pages={346 -- 359},
year={2014},
publisher={International Union of Crystallography} }

@article{mcgill2014geometry,
title={The geometry of Niggli reduction: SAUC-search of alternative unit cells},
author={McGill, Keith J and Asadi, Mojgan and Karakasheva, Maria T and Andrews, L. C. and Bernstein, H. J.},
journal={Journal of Applied Crystallography},
volume={47},
number={1},
pages={360 -- 364},
year={2014},
publisher={International Union of Crystallography} }
