Gallium is a metal with peculiar properties.
Ga does not crystallize in any of the simple [crystal structure]?s. The stable phase under normal conditions is orthorhombic? with 8 atoms in the conventional [unit cell]?. Each atom has only one nearest neighbour (at a distance of 2.44 Å) and six other neighbours within additional 0.39 Å. Many stable and metastable phases are found as function of temperature and pressure.
The melting temperature is very low, T=30 °C, and the density is higher in the liquid state than in the crystalline state (like in the case of water; the opposite effect is normally found for metals).
The bonding between the nearest neighbours is found to be of covalent? character, hence Ga2 dimers is seen as the fundamental building block of the crystal.
![[Home]](wikipedia.png)