The Oak Ridge Thermal Ellipsoid Plot (ORTEP) program is a computer program, written in Fortran, for drawing crystal structure illustrations. Ball-and-stick type illustrations of a quality suitable for publication are produced with either spheres or thermal-motion probability ellipsoids, derived from anisotropic temperature factor parameters, on the atomic sites. The program also produces stereoscopic pairs of illustrations which aid in the visualization of complex arrangements of atoms and their correlated thermal motion patterns.

ORTEP-I was distributed in 1965 and ORTEP-II in 1976 by the senior author, Carroll Johnson. There were roughly 1000 citations of the program's use for structural crytallographic publication in the 1994 CD-ROM Edition of Science Citation Index. The 1996 version, ORTEP-III, retains the philosophy of its predecessors, which is basically to provide a crystallographic language for writing a "program" (the input data file) describing the crystal structure illustration. ORTEP is noted for its versatility and high quality drawings, but it is not particularly user-friendly to a first-time user who prefers not to read documentation.

ORTEP-III Home Page

Page last revised: March 6, 1996