Potassium nickel fluoride K₂NiF₄

Unit cell

Lattice constants

a = 4.013 Å, b = 4.013 Å, c = 13.088 Å; α = 90°, β = 90°, γ = 90°

Cell volume

210.8 ų

Atoms in the cell

14 (K 4, Ni 2, F 8)

Formula units Z

2

Calculated density

3.35 g cm⁻³

Shortest contact

2.006 Å

Coordination

K

CN 9 at 2.62 Å (9 F)

Ni

CN 6 at 2.01 Å (6 F)

F

CN 2 at 2.01 Å (1.5 Ni)

About the structure

• Single perovskite layers of corner-sharing NiF₆ octahedra separated by double layers of K⁺ in rock-salt-like arrangement: the n = 1 member of the Ruddlesden–Popper series A₂BX₄.
• La₂CuO₄, the parent of the first cuprate superconductors, has exactly this structure; the two-dimensional NiF₂ sheets make K₂NiF₄ a textbook 2D antiferromagnet.
• Coordinates from the Crystallography Open Database, entry 2101024 (open data); hydrogen and water sites with partial occupancy below 0.5 are left out.

Atom positions (fractional, one cell)

Z, coordination numbers, distances, density and packing on this page are computed from these coordinates.