Bismuth selenide Bi₂Se₃

Unit cell

Lattice constants

a = 4.143 Å, b = 4.143 Å, c = 28.636 Å; α = 90°, β = 90°, γ = 120°

Cell volume

425.7 ų

Atoms in the cell

15 (Bi 6, Se 9)

Formula units Z

3

Calculated density

7.66 g cm⁻³

Shortest contact

2.851 Å

Coordination

Bi

CN 6 at 2.85 Å (6 Se)

Se

CN 4 at 3.07 Å (4 Bi)

About the structure

• Quintuple layers Se–Bi–Se–Bi–Se, each a neutral slab held to the next only by van der Waals forces; the hexagonal cell holds three slabs (rhombohedral stacking).
• A thermoelectric material and the textbook three-dimensional topological insulator: conducting surface states on an insulating bulk.
• Coordinates from the Crystallography Open Database, entry 9011965 (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.