Inter-chain and arrayed hydrogen bonds in β-1,3-d-xylan triple helix predicted by quantum mechanics calculation

β-1,3-d-xylan and β-1,3-d-glucans take the similar 6-hold right-handed triple helix. According to the classical model, three second hydroxyl groups form a hexagonal shape inter-chain hydrogen bond. Recent progress in computational chemistry proposed two other possibilities for the hydrogen bonds. Both models proposed formation of a hydrogen-bond array along the helix. The difference between them is that: one is an intra-chain and the other is an inter-chain. We compared these three models with MOPAC and B3LYP methods and concluded that the inter-chain and arrayed hydrogen bond is the most realistic one.