Derivation of the conditions for equivalent positions in crystals: The dissymmetrization of barite by electron spin resonance spectra

• Published in: Crystallography reports 2012-09, Vol.57 (5), p.751-757
• Main Authors: Khasanov, R. A., Nizamutdinov, N. M., Khasanova, N. M., Vinokurov, V. M., Morozov, G. S., Krivtsov, A. O.
• Format: Article
• Language: English
• Subjects: Crystallography and Scattering Methods; Physics; Physics and Astronomy
• ISSN: 1063-7745; 1562-689X
• DOI: 10.1134/S1063774512050070

The conditions for equivalent positions on the ( hkl ) face of growing crystal are derived using symmetry elements of the space group. It is shown by the example of the sp. gr. D 2 h 16 that the conditions of equivalent position formation coincide with conditions of the reflection of diffracted beams by crystal. It is established that electron spin resonance (ESR) centers in barite, SO 4 − (I) and SO 4 − (II), with only two conjugate spectra with equal intensity out of four, and SO 4 − (III), with a different intensity of conjugate spectra K αM = 2, are localized into the growth pyramid of the (001) face with a [010] step. SO 2 − , SO 3 − ,, and SO 4 − (IV) centers, having an identical intensity of the conjugate ESR spectra with K αM = 2, are localized into the growth pyramid of the (210) face with a growth step [001].