Programming for the prediction of physico-chemical properties of polymer

预测聚合物物理化学性质的编程

基本信息

批准号：
03555172
负责人：
IMAMURA Akira
金额：
$ 5.12万
依托单位：
HIROSHIMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03555172/
关键词：
Cluster S-SCF method Physical properties of molecule in the crystal Piezoelectricity Elongation method MOPAC Local density of states Hopping of electrons Elongation 非周期性高分子 MNDO AM1 PM3 ポリペプチド系タンパク質モデル分子 frozen軌道 active軌道

项目摘要

In order to predict physico - chemical properteis of polymers theoretically, two types of approaches have been proceedid. One of them is the approach form cluster calculations. In this cluster calculations, we developed what we called S - SCF method, by which we can predict the molecular structure in the crystal, and also the change in the dipolemoment at high pressure. The latter calculation is intimately connected with piezo - electricity.Another approach is the calculation of the electronic structure of aperiodic polymers by using the elongation method, which has been developed in our group. The elongation method is mimic to the polymerization reaction. That is, the electronic structure of aperiodic polymers is theoretically synthesized by adding a monomer to an oligomer. By this elongation method, we can obtained the electronic structure of aperiodic polymers with various length without increasing computation time. In the present, we are constructing the program package in which the elongation method is combined with various levels of molecular orbital method such as extended Huckel, CNDO/2 and MOPAC program which includes MNDO, PM3, and AM1. By using this program package, we can calculate the local density of states for aperiodic polymers, and can predict the hopping site between two polyacetylene chains. This shed light on the mechanism of electron conduction in guasi - one - dimensional conductor.

为了从理论上预测聚合物的物理化学性质，已经进行了两种类型的方法。其中之一是集群计算的方法。在这个簇计算中，我们开发了所谓的 S - SCF 方法，通过该方法我们可以预测晶体中的分子结构，以及高压下偶极矩的变化。后者的计算与压电密切相关。另一种方法是使用本课题组开发的伸长法计算非周期聚合物的电子结构。延伸方法类似于聚合反应。即，非周期聚合物的电子结构在理论上是通过将单体添加到低聚物中来合成的。通过这种伸长方法，我们可以在不增加计算时间的情况下获得不同长度的非周期聚合物的电子结构。目前，我们正在构建延伸法与各级分子轨道法相结合的程序包，如扩展Huckel、CNDO/2和MOPAC程序，其中包括MNDO、PM3和AM1。通过使用该程序包，我们可以计算非周期性聚合物的局域态密度，并可以预测两个聚乙炔链之间的跳跃位点。这揭示了电子在一维导体中传导的机制。