Exercise 1. Normal mode analysis

Diamond lattice (C, Si, Ge): Oh7, (Fd3m), ions at 0, 0, 0 and ¼, ¼, ¼.

Zinc blende Td4, (F(-)43m), different ions at 0, 0, 0 and ¼, ¼, ¼.

BaRuO3 9R; D3d5, (R(-)3m), ions at

BaRuO3 4H; D6h4, (P63/mmc)ions at