Background:structures and facts RMnO3 phases T.Goto et al. 100 PRL92,257201(2004) R=Nd paramagnetic g Sm Eu 50 eR兴 A-AF incommensurate-AF ↑ commen- ↑ RMnO3 surate 0 AF- 148 146 144 ↑ Mn-O-Mn bond angle(deg) ↓ Background: structures and facts T. Goto et al. RMnO3 phases PRL 92,257201 (2004) RMnO3 phases