Electronic structures of polymers using the tight‐binding approximation. III. Density matrix approach to poly‐L‐alanine and polyglycine‐water complex by the CNDO/2 method
Electronic structures of polymers using the tight‐binding approximation. III. Density matrix approach to poly‐L‐alanine and polyglycine‐water complex by the CNDO/2 method
复制标题
采用 CNDO/2 方法对聚-L-丙氨酸和聚甘氨酸-水复合物进行紧束缚近似的聚合物电子结构。
DOI：
10.1063/1.1681612
复制
发表时间：
1974
影响因子：
4.4
通讯作者：
H. Fujita
中科院分区：
文献类型：
--
作者：
A. Imamura;H. Fujita
在本文中，用于计算聚合物的电子结构的公式导出的密度矩阵的紧束缚近似使用CNDO/2方法。这种形式主义被成功地应用于聚-L-丙氨酸，这是很难处理的通常的SCF程序，因为发散行为的迭代计算。结果表明，右旋α螺旋构象比左旋和平面构象更稳定，与实验结果一致.总能量的分析导致发现甲基和羰基之间的相互作用决定了两个α螺旋的相对稳定性。最后，从聚合物效应的角度研究了水氢键对聚甘氨酸的影响。
In the present paper, formulas for calculating the electronic structure of polymers are derived in terms of the density matrix by the tight‐binding approximation using the CNDO/2 method. This formalism was successfully applied to poly‐L‐alanine, which was difficult to treat by the usual SCF procedure because of the divergent behavior of the iterative calculation. The obtained result indicates that the right‐handed α‐helical conformation is more stable than the left‐handed one and the planar one in agreement with experiments. The analysis of the total energy leads to the finding that the interaction between the methyl group and the carbonyl group is responsible for determining the relative stability of two α helices. Finally, the effect of water hydrogen‐bonded to polyglycine was studied from the view point of the polymer effect.