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

Abstract

The conditions for equivalent positions on the (hkl) face of growing crystal are derived using sym- metry elements of the space group. It is shown by the example of the sp. gr.D2h 16 that the conditions of equiv- alent position formation coincide with conditions of the reflection of diffracted beams by crystal. It is estab- lished that electron spin resonance (ESR) centers in barite, SO4 -(I) and SO4 -(II), with only two conjugate spectra with equal intensity out of four, and SO4 -(III), with a different intensity of conjugate spectra KaM = 2, are localized into the growth pyramid of the (001) face with a [010] step. SO2 -,SO3 -, and (IV) centers, having an identical intensity of the conjugate ESR spectra with KαM = 2, are localized into the growth pyramid of the (210) face with a growth step [001]. © Pleiades Publishing, Inc., 2012.