The crystal structure refinement of a natural mordenite

✍ Scribed by Alberti, A.; Davoli, P.; Vezzalini, G.

• Book ID: 118027002
• Publisher: Oldenbourg Wissenschaftsverlag
• Year: 1986
• Tongue: English
• Weight: 746 KB
• Volume: 175
• Category: Article
• ISSN: 2194-4946
• DOI: 10.1524/zkri.1986.175.3-4.249

✦ Synopsis

Abstract
The crystal structure of natural mordenite from Elba (Italy) with chemical formula (Na1.49K2.80Mg0.04Ca2.05Sr0.05)(Al8.98Si39.13)O96· 29.07 H2O was refined in its hydrated form up to awRvalue of 5.2%. Systematic absences were consistent with theCmcmspace group but the asymmetry of the extraframework ions indicated as more probable the acentric subgroupCmc21. Consequently the atom O8 is no longer set on an inversion center and the T – O8 – T angle is not constrained to 180°. The Si/Al distribution is partially ordered, with an enrichment of Al in the tetrahedra of the four-membered ring. All Ca ions are localized in a eight-coordinated site; K ions alternate with water molecules in a six-coordinated site.