In other words, we are creating a lot of empty space between the atoms. In order to generate the simple cubic structure, we need to place subsequent layers in such a way that they eclipse one another.

It melts at 3727 C. The stable form of carbon at room temperature is Graphite which has a hexagonal crystal structure. (Top diagram) Diamond is metastable at room temperature and has a diamond cubic ...

There are many ABO3 compounds for which the ideal cubic structure is distorted to a lower symmetry (e.g. tetragonal, orthorhombic, etc.) ...