32.7 Some Important Crystal lographic Formu as 1. Zone and zone equation All Planes parellel to common axis u v w constitute a (crystal) zone, the [u v w] zone If (h k i) belongs to zone [u v wl, then hu++ lw=0 2. If hu-tlyrly=0, then [u v wl lies in(h n 3. For cubic crystals, [h()§2.7 Some Important Crystallographic Formulas 1. Zone and zone equation All Planes parellel to common axis [u v w] constitute a (crystal) zone, the [u v w] zone. If (h k l) belongs to zone [u v w], then hu＋kv＋lw＝0 2. If hu＋kv＋lw＝0，then [u v w] lies in (h k l) 3. For cubic crystals, [h k l] ⊥(h k l)