Structure Maps of Close-Packed Layered Compounds and DNA

✍ Scribed by J. Hauck; D. Henkel; M. Klein; K. Mika

• Book ID: 102609016
• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 213 KB
• Volume: 145
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1999.8233

✦ Synopsis

Close-packed layered compounds such as Fe x Ga 2 S 3؉x and N x C 3 Al 4؉x (x ‫؍‬ 0+4) are analyzed as chains of covalent-bonded S‫؍‬Ga(+S+Fe) x +S+Ga‫؍‬S or Al C(+Al‫؍‬N) x +Al‫؍‬C‫؍‬Al (+N‫؍‬Al) x +C Al with delocalized bonds. The rules for valence compounds allow RM, R(MR) n (n‫؍‬ 1, 2, 3), RMMR, and di4erent combinations and substitutions. The conformation of the chains is characterized by the Jagodzinski+Wycko4 symbols c and h and a similar notation s and t at the occupation of tetrahedral sites. The interactions between the di4erent atoms are analyzed by structure maps with the self-coordination numbers of nearest and next-nearest neighbors as parameters. A similar analysis of 18 di4erent DNA or RNA reveals four di4erent groups within di4erent 5elds of the structure map similar to solid solutions or nonperiodic polytypes of layered compounds.