Electronic Structure of Conducting Polymers and Organic Materials

该奖项由材料研究部的材料理论计划和化学部的理论和计算化学计划资助。 本项目的目标是确定预测有机分子半导体和有机共轭聚合物基本性质的策略并进行可靠的计算。 虽然所提出的工作在很大程度上依赖于第一原理计算，在计算建模过程中的经验元素被保留和强调。 从第一性原理很难预测分子间的堆积，但堆积直接影响分子间的跳跃，这是本项目第一部分要研究的关键参数。 分子间堆积对共轭聚合物能带结构的影响是间接的，通常通过扭转自由度来发挥作用。 在这两种情况下，整合的直接或间接的实验信息包装或扭转确保的预测质量更可靠，比它将是在一个纯粹的第一原理approach.The可靠性的预测的有机分子材料是通过一个多尺度的方法，其中二聚体发挥了核心作用。 二聚体能级分裂可以用非常精确的量子化学方法来处理，一些关键影响因素的影响将被系统地研究，包括理论水平、基组和几何效应，这些影响因素将被用来预测这些材料的电子结构。对于共轭聚合物，该方法包含类似的元素，但拟议的工作集中在预测小带隙聚合物。 几种效应影响带隙，包括连接性，各种几何因素，包括偏离平面性和键定位，以及其他更多的化学性质，如杂原子和侧基。 计划包括聚合物计算机代码的方法开发，以及在具有产生非常小的带隙的潜力的特定聚合物组中的应用。这项研究有可能通过帮助寻找新的和更好的功能材料来显著影响实验研究。 该项目还涉及本科生和研究生。%该奖项由材料研究部的材料理论计划和化学部的理论和计算化学计划资助。 本项目的目标是确定预测有机分子半导体和有机共轭聚合物基本性质的策略并进行可靠的计算。 这项研究有可能通过帮助寻找新的和功能更好的材料来显著影响实验研究。 该项目还涉及本科生和研究生。

This award is funded by the Materials Theory Program in the Division of Materials Research and the Theoretical and Computational Chemistry Program in the Chemistry Division. The objective of this project is to determine strategies and perform reliable calculations for predicting the fundamental properties of organic molecular semiconductors and organic conjugated polymers. While the proposed work relies heavily on first principles calculations, empirical elements in the computational modeling process are retained and emphasized. Intermolecular packing is difficult to predict from first principles, but packing directly effects intermolecular hopping, the key parameter to be studied in the first part of this project. The effect of intermolecular packing on the band structure of conjugated polymers, the subject of the second part of this project, is indirect often exerting its effect through torsional degrees of freedom. In either case, the integration of direct or indirect experimental information on packing or torsion ensures that the quality of the predictions is more reliable, than it would be in a purely first principles approach.The reliability of the predictions for the organic molecular materials is ensured via a multi-scale approach in which dimers play a central role. The dimer level splittings can be treated with very accurate quantum chemical methods, and the effect of a number of key influences will be studied systematically, including level of theory, basis set, and geometrical effects, which will be used to predict the electronic structure of these materials.For conjugated polymers, the approach contains similar elements, but the proposed work focuses on predicting small band-gap polymers. Several effects influence the band-gap, including connectivity, various geometrical factors including deviations from planarity and bond localization, and others that are more chemical in nature such as heteroatoms and side groups. Plans include method development for a polymer computer code, and applications across specific groups of polymers that have the potential of producing very small band-gaps.This research has the potential to significantly influence experimental studies by helping to search for new and better functioning materials for device applications. The project also involves students at the undergraduate and graduate level.%%%This award is funded by the Materials Theory Program in the Division of Materials Research and the Theoretical and Computational Chemistry Program in the Chemistry Division. The objective of this project is to determine strategies and perform reliable calculations for predicting the fundamental properties of organic molecular semiconductors and organic conjugated polymers. This research has the potential to significantly influence experimental studies by helping to search for new and better functioning materials for device applications. The project also involves students at the undergraduate and graduate level.***