m

Compound

Crystal system (r.t.)

Lattice parameters (r.t.) [Å]

Soft mode

2

SrBi₂Ta₂O₉

Orthorhombic (A2₁am)

a = 5.531, b = 5.534, c = 25.98

○

3

Bi₄Ti₃O₁₂

Monoclinic (Pc)

a = 5.450, b = 5.406, c = 32.83, β ~ 90˚

○

4

SrBi₄Ti₄O₁₅

Orthorhombic (A2₁am)

a = 5.451, b = 5.437, c = 41.01

○

5

Sr₂Bi₄Ti₅O₁₈

Orthorhombic (B2cb)

a = 5.465, b = 5.463, c = 48.85

○