Cold working of sodium metal converts body centred sodium metal to a mixture of a hexagonal form and body centred sodium at 5 K. The hexagonal from converts back to the body-centred form at 100-100 K.

Cold working of lithium metal converts body centred lithium metal to a mixture of a hexagonal form and body centred lithium at 78 K.

Potassium, rubidium, and caesium retain their body centred structure after cooling

X-ray study of the alkali metals at low temperatures, Barrett, C. S. , Acta Crystallographica, 08/1956, Volume 9, Issue 8, p.671 - 677, (1956)

Lithium at room temperature is body-centered cubic with 2 atoms per unit cell. The lattice constant for lithium metal is 3.51004 ± 0.00041 Å at 25" C. The theoretical density is 533 kg m^–3 and the Li—Li bond distance for coordination number 8 is 3.0398 Å.

SMILES: [Li]
InChI: InChI=1/Li

Crystallographic Data 186. Lithium, Nadler, M. R. /, and Kempier C. P. , Analytical Chemistry, 12/1959, Volume 31, Issue 12, p.2109 - 2109, (1959)