Publisher Summary This chapter provides projection diagrams to illustrate the conformation of the organic molecule or ion. These diagrams are produced, by means of computer graphics, directly from the unit-cell dimensions and the atomic co-ordinates of the molecules in the crystal structures. For the carbohydrates, carbon and hydrogen atoms are shown as small, solid circles and other atoms by the appropriate symbol. The CRYSNET software is used to rotate the molecular diagrams so as to correspond as closely as possible to the conventional, conformational diagrams used in the carbohydrate literature. For the nucleosides and nucleotides, the ORTEP programs are used, with the following atom designations: carbon, open circle; hydrogen, small open circle; oxygen, solid circle; nitrogen, hatched circle; sulfur, dotted circle; and halogen, cross-hatched circle.