Le groupe P1 et ses sous-groupes. II. Tables de sous-groupes

This paper is the continuation of another paper devoted to the theoretical aspects and properties of isomorphic subgroups of P1 and p1 [Billiet (1979). Acta Cryst. A35, 485-496]. In the present paper the determination of the number of these subgroups is investigated with practical results for all indices up to 30. The theoretical construction of typical conventional unit cells is also studied: these typical unit cells are obtained by means of suitable triangular matrices. The isomorphic subgroups of P1 and their conventional unit cells are tabulated for all indices up to 7 (234 subgroups, 597 unit cells). Analogous data are tabulated for isomorphic subgroups of p1 (40 subgroups, 65 unit cells).