Abstract
Crystals upon transition or inversion often produce in their secondary phase a complicated twin which simulates a single crystal. The twinned crystal commonly consists of a super-structure based upon the primary form and the twinning is produced by the twin laws closely related to the symmetry of the primary form. Such a crystal shows a complex diffraction pattern, and it is generally difficult to distinguish the contribution by one individual from the others. An algebraic method for analysing these diffraction patterns through examination of the mode of distribution of satellite reflections is proposed and discussed in relation to the subsequent procedures such as structure determination and refinement.
