  Redundancies are pointed out in the widely used extension of the
crystallographic concept of Bravais class to quasiperiodic materials. Such
pitfalls can be avoided by abandoning the obsolete paradigm that bases ordinary
crystallography on microscopic periodicity. The broadening of crystallography
to include quasiperiodic materials is accomplished by defining the point group
in terms of indistinguishable (as opposed to identical) densities.

High Energy Physics - Theory