水楊醛 構形異構物 分子內氫鍵 官能基間氫鍵 官能基內氫鍵 區域化氫鍵鍵能及鍵次分析法 MP2/6-31G[fec8][fec8]法 Salicylaldehyde Conformer isomers Intramolecular hydrogen bond Interfunctional groups hydrogen bond Intrafunctional group hydrogen bond Localized hydrogen bond energy and bond order analysis MP2/6-31G[fec8][fec8]