Exercise 1. Normal mode analysis Diamond lattice (C, Si, Ge): O h 7 , (Fd3m), ions at 0, 0, 0 and ¼, ¼, ¼. Zinc blende T d 4 , (F(-)43m), different ions at 0, 0, 0 and ¼, ¼, ¼. BaRuO 3 9R; D 3d 5 , (R(-)3m), ions at BaRuO 3 4H; D 6h 4 , (P6 3 /mmc)ions at