An Analytical Treatment of the Geometrical Properties of the Three-circle Goniometer

Abstract

The use of the three-circle goniometer for X-ray or neutron crystallography is described briefly. Equations are derived using vectorial methods for the computation of the angle settings of the instrument for three-dimensional data collection. These equations are derived for both procedures used in practice, namely, where the (h k 1) vector in reciprocal space is brought into coincidence with the scattering vector or when each zone a..-,;:is [u v w] is brought into coincidence with the axis of rotation of the diffractometer.