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Optical phonons in α‐NiSO 4 ·6H 2 O single crystal
Author(s) -
Jain Y. S.,
Bist H. D.,
Verma A. L.
Publication year - 1974
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1250020402
Subject(s) - raman spectroscopy , phonon , crystallography , crystal (programming language) , excited state , crystal structure , polyhedron , symmetry (geometry) , physics , chemistry , materials science , condensed matter physics , atomic physics , optics , geometry , mathematics , computer science , programming language
Laser excited Raman spectra of a single crystal of α‐NiSO 4 ·6H 2 O have been attributed to the phonons originating only from the Raman active modes of isolated H 2 O ( C 2 v ), SO 4 2−( T d ) and Ni(H 2 O) 6 2+( O h ) units. It has been shown that T h symmetry considered earlier for NI(H 2 O) 6 2+complex by Jager and Schaack is not consistent with the crystal structure of α‐NiSO 4 ·6H 2 O and results in an erroneous symmetry classification of 288 phonon branches of the unit cell. A correct classification of these branches is reported. It is inferred that the SO 4 2−and Ni(H 2 O) 6 2+polyhedra do not show large distortions from their respective T d and O h symmetries at room temperature.