Almost Crystallographic Groups - A Library and Algorithms

Version 1.3.2
Released 2020-01-28

This project is maintained by Bettina Eick

Aclib -- A Library of 3- and 4-Dimensional Almost Crystallographic Groups

by Karel Dekimpe and Bettina Eick


The package `aclib' contains the almost crystallographic groups as 
classified by K. Dekimpe in the Springer Lecture Notes, Vol. 1639: 
"Almost Bieberbach Groups: Affine and Polynomial Structures". 

The groups are available as rational matrix groups. Further, all the
groups in the library are polycyclic. If the `Polycyclic' package for 
computations with infinite polycyclic groups is installed, then also
polycyclic presentations for the almost crystallographic groups are
available and can be used for computations with these groups.

Please report any problems you may encounter using `aclib' at


The `aclib' package is licensed under the Artistic License 2.0.