K₂NiF₄

Unit cell

Lattice constants

a = 4.000 Å, b = 4.000 Å, c = 13.070 Å; α = 90.00°, β = 90.00°, γ = 90.00°

Cell volume

209.1 ų

Atoms in the conventional cell

14 (Ni 2, F 8, K 4)

Formula units Z

2

Pearson symbol

tI14 — tetragonal, body-centred lattice, 14 atoms per conventional cell

Symmetry operations

32 per cell

Crystallographic sites

The multiplicity and the Wyckoff letter say how many copies of the site the group makes in one cell and on which kind of symmetry element the site sits; the 14 atoms drawn above are these sites multiplied by all 32 operations. Press Wyckoff under Colour to see the sites, and tick a symmetry element on the left to see which atoms lie on it.

How to read the label

A4B2C_tI14_139_ce_e_a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI14, then the space-group number 139, then the Wyckoff letters occupied by each element in turn (Ni: 2a; F: 4c; F: 4e; K: 4e). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Ba₂SnO₄, Ba₂ZrS₄, Ca₂MnO₄, Cs₂CrCl₄, Cs₂CrF₄, Cs₂CuCl₄, Cs₂CuF₄, K₂CrCl₄, K₂CrF₄, K₂CuCl₄, K₂CuF₄, La₂NiO₄, La₂PdO₄, Nd₂CuO₄, Sr₂IrO₄, Sr₂MnO₄, Sr₂RuO₄, Sr₂SnO₄, Sr₂TiO₄, Sr₂VO₄, (Fe, La)₂SrO₄, (Sr, La)₂AlO₄, (Sr, La)₂CoO₄ <!--beginning with an

Note: Ruddlesden-Popper.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A4B2C_tI14_139_ce_e_a-001 (M. J. Mehl et al., Comput. Mater. Sci. 136, S1 (2017); D. Hicks et al., ibid. 161, S1 (2019) and 199, 110450 (2021); S. Eckert et al., ibid. 240, 112988 (2024)). Symmetry elements, Wyckoff assignment and the diagram are computed on this page from the group operations.