Powder samples of the intermediate phase between sodalite and cancrinite (INT) have been synthesized hydrothermally. The formation of the INT phase was proved by both PXRD and TGA analysis and its stoichiometric composition was found to be |Na6.95(1)(CO3)0.48(2) (H2O)6.18(6)|[AlSiO4]6. The comparison of the intensity ratios of PXRD data with a SCXRD measurement indicates the formation of a comparable phase with the typical strong stacking disorder. The hexagonal lattice parameters with a=1266.3(2) pm and c=1586(1) pm and the unit cell setting were determined by Pawley fits. The average lattice and the stacking disorder along c axis could be confirmed by the reconstruction of three-dimensional ADT data. The average structure of INT was modeled considering only the combination of naturally existing (zeolitic) cages, restricted by the actual number of layers per unit cell. The possible combinations were further reduced by considering the amount of incorporated species. Through the comparison of simulated electron diffraction pattern to measured data the modeled framework could be confirmed. Using relative positions of the incorporated species in the natural cages as well as electron densities calculated by using only the framework of INT the positions of these species could be described.
The authors are very thankful to J.-C. Buhl for providing INT single crystals used in this work and to C. Weidenthaler and J. Ternieden (Max-Planck-Institut für Kohlenforschung) for providing PXRD data in a time of need. We gratefully acknowledge the German science foundation (DFG) for support in the large facility program; project numbers INST144/435-1 FUGG and INST144/458-1 FUGG. Haishuang Zhao is grateful to the financial support from Carl-Zeiss-Stiftung. The authors thank the two anonymous reviewers for their comments, which greatly improved the paper.
 I. Hassan, Can. Mineral.1996, 60, 949.Search in Google Scholar
 P. Lotti, Cancrinite-Group Minerals at Non-Ambient Conditions: A Model of the Elastic Behavior and Structure Evolution, 2013.Search in Google Scholar
 E. A. Pobedimskaya, L. E. Terent’eva, A. N. Saphozhinkov, A. A. Kashaev, G. I. Dorokhova, Sov. Phys. Dokl.1991, 36, 553.Search in Google Scholar
 P. Ballirano, S. Merlino, E. Bonaccorsi, Can. Mineral.1996, 34, 1021.Search in Google Scholar
 H. Zhao, Y. Krysiak, K. Hoffmann, B. Barton, L. Molina-Luna, R. B. Neder, H. J. Kleebe, T. M. Gesing, H. Schneider, R. X. Fischer, U. Kolb, J. Solid State Chem.2017, 249, 114.10.1016/j.jssc.2017.02.023Search in Google Scholar
 P. Krishna, D. Pandey, Close-Packed Structures, 2001st ed., University College, Cardiff Press, Wales University College, Cardiff, 1981.Search in Google Scholar
 Materials Studio. Accelrys Software Inc., San Diego, 2009.Search in Google Scholar
 Y. I. Smolin, Y. F. Shepelev, I. K. Butikova, I. B. Kobyakov, Kristallografiya1981, 26, 63.Search in Google Scholar
The online version of this article offers supplementary material (https://doi.org/10.1515/zkri-2018-2114).
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