Theoretical Study on New Optical Functional Material by Unified Simulation Techniques

应用对相互作用近似(碎片分子轨道理论：FMO)建立了一个评价大分子体系光学性质的量子化学程序系统。通过引入交换泛函中的长程修正，进一步解决了密度泛函理论评价大分子极化率的一个长期存在的问题。在FMO框架下，利用响应理论对偶氮树状大分子的线性和非线性光学性质进行了非经验计算。发现了表示部分电荷转移的单位之间具有量子修正的简单加法规则。建立了统一的量子粒子和经典粒子混合物的溶剂化密度泛函理论。该理论已成功地应用于流体中过剩电子离域、聚合物链在超临界溶剂中的反常行为以及正电子湮没速率在超临界流体中的显著提高等问题。

Pair interaction approximation (Fragment Molecular Orbital Theory:FMO) is applied for developing a quantum chemical ; program system for evaluating optical property of large molecular systems. A new functional for accounting weak force such as van der Waals is introduced Further a long standing problem of Density Functional Theory for evaluating polarizability of large molecules is resolved by introducing a long range correction in exchange functional. The non-empirical calculations are performed for evaluation of linear and non-linear optical properties of Azo-dendrimer using response theory within the FMO framework. Simple addition rule with a quantum correction between units representing partial charge transfer is found. A unified density functional theory for solvation is formulated for quantum and classical particle admixtures. The theory is successfully applied for the problems such as delocalization of excess electron in fluids, anomalous behavior of polymer chain in supercritical solvents and an remarkable increase of positron annihilation rate in supercritical fluid.