This book contains the contributions of 13 well known specialists in the field of solid state chemistry who had been invited as lecturers at a 1992 NATO Advanced Study Institute in Erice, Sicily. The chapters of a more general character concern the use of the space group - subgroup relationships for the recognition of structure families, the crystal chemical formulae (which is a way of denoting simple crystal chemical information in a condensed form), the concepts of atom co-ordination, atom volume and charge transfer and the physicist's view of the bond strength in the solid which is...