文献类型：期刊文献

英文题名：Electronic Energy Gaps for π-Conjugated Oligomers and Polymers Calculated with Density Functional Theory

作者：Sun, Haitao[1,2];Autschbach, Jochen[1]

机构：[1]SUNY Buffalo, Dept Chem, Buffalo, NY 14260 USA;[2]E China Univ Sci & Technol, Shanghai Key Lab Adv Polymer Mat, Key Lab Ultrafine Mat, Minist Educ,Sch Mat Sci & Engn, Shanghai 200237, Peoples R China

年份：2014

卷号：10

期号：3

起止页码：1035

外文期刊名：JOURNAL OF CHEMICAL THEORY AND COMPUTATION

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000332913500016)】；

基金：We would like to thank the Center for Computational Research (CCR) at the University at Buffalo for providing computational resources. HS gratefully acknowledges financial support of the China Scholarship Council. J.A. acknowledges support from grants CHE-0952253 and CHE-1265833 of the National Science Foundation.

语种：英文

摘要：In varying contexts, the terms "energy gap" (energy difference) or "band gap" may refer to different experimentally observable quantities or to calculated values that may or may not represent observable quantities. This work discusses various issues related to calculations of electronic energy gaps for organic pi-conjugated oligomers and linear polymers by density functional theory (DFT). Numerical examples are provided, juxtaposing systematic versus fortuitous agreement of orbital energy gaps with observable fundamental (ionization vs electron attachment) or optical (electronic excitation) energy gaps. Successful applications of DFT using nonempirically tuned hybrid density functionals with range-separated exchange (RSE) for calculations of optical gaps, fundamental gaps, and electron attachment/detachment energies are demonstrated. The extent of "charge-transfer like" character in the longest-wavelength singlet electronic excitations is investigated.