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International
Tables for Crystallography Volume B Reciprocal space Edited by U. Shmueli © International Union of Crystallography 2006 |
International Tables for Crystallography (2006). Vol. B. ch. 3.3, p. 380
Section 3.3.3.1.1. ORTEP
aMRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, England |
This program, the Oak Ridge Thermal Ellipsoid Program, due to Johnson (1970![[link]](/graphics/greenarr.gif)
, 1976) was developed originally for the preparation of line drawings on paper though versions have since been developed to suit raster devices with interactive capability.
The program draws molecules in correct perspective with each atom represented by an ellipsoid which is the equi-probability surface for the atomic centre, as determined by anisotropic temperature factor refinement, the principal axes of which are displayed. Bonds are represented by cylindrical rods connecting the atoms which in the drawing are tapered by the perspective.
In line-drawing versions the problem of hidden-line suppression is solved analytically, whereas the later versions for raster devices draw the furthest elements of the picture first and either overwrite these with nearer features of the scene if area painting is being done or use the nearer features as erase templates if line drawings are being made.
References
Johnson, C. K. (1970). Drawing crystal structures by computer. In Crystallographic computing, edited by F. R. Ahmed, pp. 227–230. Copenhagen: Munksgaard.Google Scholar
Johnson, C. K. (1976). ORTEPII. A Fortran thermal-ellipsoid plot program for crystal structure illustrations. Report ORNL-5138. Oak Ridge National Laboratory, Tennessee, USA.Google Scholar
