A computer program that calculates irteratomic distances, bond angles, principal axes of thermal motion, and other functions of the unit cell parameters, the atomic coordinates, and the temperature factor coefficients of a crystal structure is described. The standard errors of these functions are computed from the variancecovariance matrix of the parameters if this is known. The program may be used independently, or the input may be taken from a magnetic tape prepared by the crystallographic least-squares program OR FLS. The program is written entirely in Fortran, and detailed instructions for its use are included. (auth)