  Niggli reduction can be viewed as a series of operations in a six-dimensional
space derived from the metric tensor. An implicit embedding of the space of
Niggli-reduced cells in a higher dimensional space to facilitate calculation of
distances between cells is described. This distance metric is used to create a
program, BGAOL, for Bravais lattice determination. Results from BGAOL are
compared to the results from other metric-based Bravais lattice determination
algorithms.
