甘氨酸与水分子间相互作用的理论研究

在密度泛函(DFT)B3LYP/6_311++G(3d,3p)水平,对中性甘氨酸的最小点结构Ip和H2O分子间可能存在的氢键复合物进行全自由度能量梯度优化,发现了三个氢键极小结构A、C和E,其中结构A为最稳定结构,它是H2O与甘氨酸的羧基(-COOH)形成两个氢键的结构,具有C1对称性.分别采用密度泛函理论(DFT)和MP2方法,在6-311++G(3d,3p)水平,对结构A的结构和结合能进行了比较计算,得到结合能ΔEDFT为-41.88 kJ/mol,ΔEMP2为-40.34 kJ/mol.

Theoretical studies on the interaction between glycine and H2O

the interaction between the global minimum of nonionized glycine (Ip) and H 2O was investigated employing density functional theory (DFT) and MP2 theoretical methods, using Pople's standard 6-311++G(3d,3p) basis set. Three equilibrium structures (A, C and E) of the glycine (Ip) and H 2O complex were finally obtained. The conformer A, which H 2O is internally doubly H bonded to the carboxyl of glycine, is the most stable one among the three condormers. The geometry and the binding energy of A were calculated at DFT/B3LYP and MP2 theory levels. The binding energy of A were calculated at DFT/B3LYP and MP2 theory levels. The binding energy is -41.88 kJ/mol at the DFT/B3LYP and -40.34 kJ/mol at the MP2 level, respectively.