Topic summary
BeO
Extracted from the Wikipedia article Beryllium oxide.
Structure
BeO crystallizes in the hexagonal wurtzite structure, featuring tetrahedral Be and O centres, like lonsdaleite and w-BN (with both of which it is isoelectronic). In contrast, the oxides of the larger group-2 metals, i.e., MgO, CaO, SrO, BaO, crystallize in the cubic rock salt motif with octahedral geometry about the dications and dianions. At high temperature the structure transforms to a tetragonal form.