[2] It adopts a monoclinic crystal structure in space group P 21/c (no.

[3][4] It also adopts an orthorhombic polymorph in space group Pbca (no.

[5] A third polymorph of europium(II) iodide is formed if it is prepared from europium and ammonium iodide at low temperatures (200 K) in liquid ammonia.

This low-temperature phase is orthorhombic and in space group Pnma (no.

This is the same structure as modification IV of strontium iodide.