Volume 9 (1980)

Editorial

• A. Kerber, pp. VII-VII

Reports and Reviews

ZiF-Conference on Crystallographic Groups

• A. W. M. Dress, J. Neubueser: Foreword, pp. 3-3
• List of Participants, pp. 7-10

Generalized Crystallographic Groups

• H. B. Buergi: Space Group-Like Symmetries in the Conformational Analysis of Flexible Molecules, pp. 13-14
• A. W. M. Dress: A Mathematical Note on Koptsik's Definition of Imperfect Crystals, pp. 15-20
• K. Fichtner: On Groupoids in Crystallography, pp. 21-40
• J. N. Kotzev: On the New Types of Colour Symmetry Groups, pp. 41-50
• W. Opechowski: Reamrks on Metacrystallographic Groups, pp. 51-64

Geometric Aspects of Crystal Structures

• H. S. M. Coxeter: Higher-Dimensional Analogues of the Tetrahedrite Crystal Twin, pp. 67-72
• M. S. Delaney: Quasi Symmetries of Space Group Orbits, pp. 73-80
• A. W. M. Dress: On the Classification and Generation of Two- and Higher-Dimensional Regular Patterns, pp. 81-100
• W. Fischer: Normal Homogeneous Partitions of Three-Dimensional Euclidean Space which are not Partitions into Fundamental Regions of a Space Group, pp. 101-101
• W. Fischer: On a Space-Filling Polyhedron with 26 Faces, pp. 103-103
• W. E. Klee: Topological Aspects of Crystallography, pp. 105-120
• H. Wondratschek: Crystallographic Orbits, Lattice Complexes, and Orbit Types, pp. 121-125
• H. Zassenhaus: On the Sphere Packing Problem, pp. 127-135

Subgroup Relations

• H. Baernighausen: Group-Subgroup Relations between Space Groups: A Useful Tool in Crystal Chemistry, pp. 139-175
• Y. Billiet: The Subgroups of Finite Index of the Space Groups: Determination via Conventional Coordinate Systems, pp. 177-190
• K. J. Koehler: Subgroup-Relations between Crystallographic Groups, pp. 191-207

Representation Theory

• N. Backhouse: An Equivalence Test for Multipliers of Projective Representations of Solvable Groups, pp. 211-217
• N. Backhouse: Clifford Theory and Its Application to the Representation Theory of Crystallographic Space Groups, pp. 219-225
• A. P. Cracknell: Irreducible Representations of Point Groups and Space Groups - The Last 50 Years and the Next 10 Years, pp. 227-241
• R. Dirl: Selection Rules for Magnetic Groups. Application to Type II Shubnikov Space Groups, pp. 243-256
• J. N. Kotzev, M. I. Aroyo: Clebsch-Gordan Coefficients for the Corepresentations of Shubnikov Point Groups, pp. 257-258