文献类型：期刊文献

英文题名：Influence of the Delocalization Error and Applicability of Optimal Functional Tuning in Density Functional Calculations of Nonlinear Optical Properties of Organic Donor-Acceptor Chromophores

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, Sch Mat Sci & Engn, Shanghai Key Lab Adv Polymer Mat, Key Lab Ultrafine Mat,Minist Educ, Shanghai 200237, Peoples R China

年份：2013

卷号：14

期号：11

起止页码：2450

外文期刊名：CHEMPHYSCHEM

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000322339100016)】；

基金：We acknowledge the Center for Computational Research (CCR) at the University at Buffalo for providing computational resources. H. S. gratefully acknowledges financial support of the China Scholarship Council and technical assistance by Barry Moore II and Ben Pritchard. J.A. thanks Prof. Dr. L. Kronik for constructive comments on the manuscript. We thank Dr. N. Govind for making functionality for plots of the transition density available to us. This work received support from grant CHE-0952253 of the National Science Foundation.

语种：英文

外文关键词：charge transfer; chromophores; density functional calculations; donor-acceptor systems; nonlinear optics

摘要：Nonempirically tuned hybrid density functionals with rangeseparated exchange are applied to calculations of the first hyperpolarizability (b k) and charge-transfer (CT) excitations of linear " push-pull" donor-acceptor-substituted organic molecules with extended p-conjugated bridges. An unphysical delocalization with increasing chain length in density functional calculations can be reduced significantly by enforcing an asymptotically correct exchange-correlation potential adjusted to give frontier orbital energies representing ionization poten-tials. The delocalization error for a number of donor-acceptor systems is quantified by calculations with fractional electron numbers and from orbital localizations. Optimally tuned hybrid variants of the PBE functional incorporating range-separated exchange can produce similar magnitudes for b k as MollerPlesset second-order perturbation (MP2) correlated calculations. Improvements are also found for CT excitation energies, with results similar to an approximate coupled-cluster model (CC2).