ORDINARY ORGANIC-CRYSTAL CHEMISTRY - INTERPRETATION OF THE MOST PROBABLE HOMOMOLECULAR STRUCTURES

For homomolecular organic crystals, most characteristic types of molec ular arrangement corresponding to most widespread structural classes a nd subclasses are named and interpreted. these characteristic structur al variants cover about 70% of crystal substances consisting of chemic ally identical molecules. Examples of crystal structures are cited to illustrate the structural laws of organic crystals; the structures are given as easily perceptible representations taken front the album ''S tructure of Organic Crystals. '' An important structural feature of or dinary molecular crystals is coexistence of molecules with four or two different orientations (64 and 28%, respectively). Basic notions and approaches of modem organic crystal chemistry are briefly defined.