Rotations, Quaternions, and Double Groups

Quaternions are a simple and powerful tool for handling rotations and double groups. This book gives a complete treatment of finite point groups as subgroups of the full rotation group and emphasizes geometrical and topological methods which permit a unique definition of the quaternion parameters for all operations of such groups. An important feature of the book is an elementary but comprehensive discussion of projective representations and their application to the spinor representations. This gives great advantages in conciseness and precision over the more classicl double group method. The treatment throughout is self-contained although some familiarity with elementary group theory is assumed.