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Similarities and peculiarities between the crystal structures of the hydrates of sodium sulfate and selenate
Author(s) -
Kamburov Stoyan,
Schmidt Horst,
Voigt Wolfgang,
Balarew Christo
Publication year - 2014
Publication title -
acta crystallographica section b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.604
H-Index - 33
ISSN - 2052-5206
DOI - 10.1107/s2052520614007653
Subject(s) - monoclinic crystal system , crystallography , tetragonal crystal system , crystal structure , chemistry , selenate , crystal (programming language) , atom (system on chip) , selenium , organic chemistry , computer science , programming language , embedded system
The crystal structures of the two hydrates Na 2 SeO 4 ·10H 2 O and Na 2 SeO 4 ·7.5H 2 O are studied for the first time. The structures of Na 2 SO 4 ·10H 2 O and Na 2 SO 4 ·7H 2 O are reinvestigated as a function of temperature with respect to the degree of disorder of the O atoms of in the decahydrate and the O atom of water in the heptahydrate. For Na 2 SO 4 ·10H 2 O, the unit site occupancy factor (SOF) of O atoms of was determined at 120 K. After the temperature dependence of the lattice parameters was studied from 120 to 260 K, it was shown that SOF decreased from 1.0 at 120 K to 0.247 at room temperature. The interesting fact that two salts with different chemical compositions and different crystal structures (Na 2 SO 4 ·7H 2 O, tetragonal, space group P 4 1 2 1 2 and Na 2 SeO 4 ·7.5H 2 O, monoclinic, space group C 2 /c ) can act mutually as a crystal nucleus is accounted for by similarities in certain fragments of their crystal structures. This phenomenon is attributed to similarities between particular elements of their structures.