Caesium chloride CsCl

Unit cell

Lattice constants

a = 4.123 Å, b = 4.123 Å, c = 4.123 Å; α = 90°, β = 90°, γ = 90°

Cell volume

70.1 ų

Atoms in the cell

2 (Cs 1, Cl 1)

Formula units Z

1

Calculated density

3.99 g cm⁻³

Shortest contact

3.571 Å

Coordination

Cs

CN 8 at 3.57 Å (8 Cl)

Cl

CN 8 at 3.57 Å (8 Cs)

About the structure

• Simple cubic array of Cl⁻ with Cs⁺ in the cubic hole (or the reverse — the two are equivalent).
• Coordination 8:8; radius ratio r⁺/r⁻ ≈ 0.93, above the 0.732 limit for a cube.
• Not body-centred cubic: the corner and centre atoms are different.
• CsBr, CsI, TlCl, NH₄Cl share this structure.

Atom positions (fractional, one cell)

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