Bravais Lattices

Most solid materials are crystalline, with their component atoms and molecules arranged in regular arrays throughout space. The French scientist Auguste Bravais showed that there are only 14 different ways of doing this, called the Bravais lattices, each with different symmetry. In other words, there is a Bravais equation for the number of different lattices: N L = 14. This chapter examines the relationship between Bravais lattices, crystal systems and symmetry groups, the use of Miller indices to describe crystal planes and directions, and the use of stereograms to describe crystal orientations. Bravais’ early life in the Ardèche in France is described, along with his exciting career during and after the French Revolution: as an officer in the French navy during the Barbary wars; as an explorer in North Africa, the Arctic and the Alps, notably leading the second scientific ascent of Mont Blanc; and as an environmental, geophysical and crystallographic scientist.