Тип публикации: статья из журнала

Год издания: 2017

Идентификатор DOI: 10.1107/S2052520616020680

Ключевые слова: carbonates, incommensurately modulated structures, minerals, nyerereite, twinning, X-ray analysis

Аннотация: The incommensurately modulated twin structure of nyerereite Na1.64K0.36Ca(CO3)2 has been first determined in the (3+1)-dimensional symmetry group Cmcm(α00)00s with modulation vector q = 0.383a∗. Unit-cell values are a = 5.062(1), b = 8.790(1), c = 12.744(1) Å. Three orthorhombic components are related by threefold rotation about [0Показать полностью01]. Discontinuous crenel functions are used to describe the occupation modulation of Ca and some CO3 groups. The strong displacive modulation of the O atoms in vertexes of such CO3 groups is described using x-harmonics in crenel intervals. The Na, K atoms occupy mixed sites whose occupation modulation is described in two ways using either complementary harmonic functions or crenels. The nyerereite structure has been compared both with the commensurately modulated structure of K-free Na2Ca(CO3)2 and with the widely known incommensurately modulated structure of γ-Na2CO3. The incommensurately modulated twin structure of nyerereite Na1.64K0.36Ca(CO3)2 has been first determined and then compared with the modulated structure of γ-Na2CO3. © International Union of Crystallography, 2017.

Журнал: Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials

Выпуск журнала: Vol. 73, Is. 2

Номера страниц: 276-284

ISSN журнала: 20525192

Издатель: International Union of Crystallography

• Bolotina N.B. (Shubnikov Institute of Crystallography, Federal Scientific Research Centre Crystallography and Photonics of Russian Academy of Sciences, Leninskii prosp. 59, Moscow, Russian Federation)
• Gavryushkin P.N. (Sobolev Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences, prosp. acad. Koptyuga 3, Novosibirsk, Russian Federation, Novosibirsk State University, Pirogova st. 2, Novosibirsk, Russian Federation)
• Korsakov A.V. (Sobolev Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences, prosp. acad. Koptyuga 3, Novosibirsk, Russian Federation, Novosibirsk State University, Pirogova st. 2, Novosibirsk, Russian Federation)
• Rashchenko S.V. (Sobolev Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences, prosp. acad. Koptyuga 3, Novosibirsk, Russian Federation, Novosibirsk State University, Pirogova st. 2, Novosibirsk, Russian Federation)
• Seryotkin Y.V. (Sobolev Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences, prosp. acad. Koptyuga 3, Novosibirsk, Russian Federation, Novosibirsk State University, Pirogova st. 2, Novosibirsk, Russian Federation)
• Golovin A.V. (Sobolev Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences, prosp. acad. Koptyuga 3, Novosibirsk, Russian Federation, Novosibirsk State University, Pirogova st. 2, Novosibirsk, Russian Federation, Diamond and Precious Metal Geology Institute, Siberian Branch of Russian Academy of Sciences, Lenina Pr. 39, Yakutsk, Russian Federation)
• Moine B.N. (Laboratoire Magmas et Volcans, UMR6524 CNRS Université J. Monnet, 23 rue du Dr. P. Michelon, Saint-Etienne, France)
• Zaitsev A.N. (Department of Mineralogy, St. Petersburg State University, University Emb. 7/9, St Petersburg, Russian Federation, Department of Earth Sciences, Natural History Museum, Cromwell Road, London, United Kingdom)
• Litasov K.D. (Sobolev Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences, prosp. acad. Koptyuga 3, Novosibirsk, Russian Federation, Novosibirsk State University, Pirogova st. 2, Novosibirsk, Russian Federation)

• Scopus