Electron crystallographic study of a kaolinite single crystal

•We applied new techniques of electron crystallography for structure determination.•The structure of kaolinite single crystal was determined and refined.•The structure of the studied kaolinite is described in the non-conventional C1 sg.•Single crystal structure determination of submicron-sized clay minerals is attainable.

Kaolinite is an abundant micro- and submicrometer-sized sheet silicate [Al2Si2O5(OH)4] built up of alternating tetrahedral (T) and octahedral (O) sheets. Except for Neder et al.'s (1999) single-crystal synchrotron study, X-ray and neutron diffraction methods were used for structural measurements on powdered samples. The aim of the present work is to provide a second single crystal structure determination on a kaolinite using recently developed electron diffraction techniques of electron crystallography.Using precession electron diffraction (PED, Vincent and Midgley, 1994; Avilov et al., 2007) and electron-diffraction tomography (Kolb et al., 2007, 2008) techniques, a 3D diffraction data set was acquired. The crystal structure was determined in SIR2011 and refined in SHELXL97 software. The crystal structure of the studied kaolinite is described in the non-conventional C1 space group with unit cell parameters: a = 5.21(1) Å, b = 9.12(2) Å, c = 7.48(2) Å, α = 88.7(2)°, β = 104.2(2)°, γ = 90.3(2)°.