Crystal Structure Archive

On this page you will find links to download CIFs (Crystallographic Information Files) that contain crystallographic structural data for structures that I have studied.

Important: Most browsers will download these files. If your browser opens the file, just right-click on the link and select save link as or save target as in IE.

Alkali Feldspars

In a paper Structural controls on the anisotropy of tetrahedral frameworks: the example of monoclinic feldspars" by Angel R.J., Ross N.L., Zhao J., Sochalski-Kolbus L.M., Krüger H., Schmidt B.C. (2013) in European Journal of Mineralogy we compiled all of the structures of monoclinic "alkali" feldspars refined at ambient pressure that we were able to locate in the literature. We use the term "alkali feldspars" for all alumino-silicate feldspars with a framework content of AlSi3, and thus an extra-framework cation of formal charge +1. Feldspars with Li, Rb, NH4, H and Tl are therefore also included in the CIFs. The CIFs contain structures determined at high-temperature as well as at ambient temperature, but does not include high-pressure data.

If you find any further refined structures in the literature, or are willing to donate unpublished structural data, please contact us.

The structures are contained in two CIFs, along with 10 new structures refined and published for the first time in that paper.

Alkali_mono_ok.cif contains all refined structures of alkali feldspars refined at ambient pressure that appear to be correct.

Alkali_mono_anom.cif contains 7 published structures of alkali feldspars that appear to be anomalous. For a full description see Angel et al. (2013)

Plagioclase Feldspars

Elasticity of Plagioclase Feldspars by Brown, Angel & Ross, Journal of Geophysical Research, Solid Earth (2016) reports the full elastic tensors of 7 plagioclase feldspars along with the elastic tensor of albite.

The structures of six intermediate plagioclase crystals were refined for this paper, available for download.

Miscellaneous structures

Back in 1996 we reported in Angel RJ, Ross NL, Seifert F, Fliervoet TF (1996) Structural characterization of pentacoordinate silicon in a calcium silicate. Nature 384:441-444 (1996) the single-crystal structure of the first crystalline phase synthesised with silicon five-coordinated by oxygen.

The structure is interesting because it also contains SiO4 and SiO6 groups as well as SiO5 pentagonal pyramids. You can download a cif of the structure.