Barium titanate (tetragonal) BaTiO₃

Unit cell

Lattice constants

a = 3.991 Å, b = 3.991 Å, c = 4.025 Å; α = 90°, β = 90°, γ = 90°

Cell volume

64.1 ų

Atoms in the cell

5 (Ti 1, O 3, Ba 1)

Formula units Z

1

Calculated density

6.04 g cm⁻³

Shortest contact

1.884 Å

Coordination

Ti

CN 6 at 1.88 Å (6 O)

O

CN 2 at 2.00 Å (2 Ti)

Ba

CN 12 at 2.77 Å (12 O)

About the structure

• The room-temperature form of BaTiO₃: the cubic perovskite cell is stretched along c (c/a = 1.01) and Ti⁴⁺ is displaced off the centre of its octahedron, giving a permanent dipole.
• That dipole can be switched by a field — ferroelectricity — which is why BaTiO₃ is the dielectric of multilayer ceramic capacitors. Above 120 °C it becomes cubic (see the ideal perovskite entry).
• Coordinates from the Crystallography Open Database, entry 1525437 (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.