Accurate lattice constants from multiple diffraction measurements. I. Geometry, techniques and systematic errors

A procedure for the determination of lattice constants, accurate to from 1 to 4 parts per million, from measurements of multiple diffraction peak locations is described. Experimental techniques and systematic errors are discussed. Large numbers of multiple diffraction peaks become available for measurement in the course of 360° of rotation about one axis. The method can be used with wide ranges of crystal sizes, shapes and degrees of perfection.