A density functional theory framework is developed to study electronic excited states affected by an anisotropic dielectric environment. In particular, an anisotropic dielectric screened range-separated hybrid (SRSH[r]) functional is defined and combined with an anisotropic polarizable continuum model (PCM) implemented through a generalized Poisson equation solver. We develop the SRSH-PCM(r) approach and use it to quantify the effect of anisotropy on an excited charge transfer (CT) state energy. In particular, the dielectric interface effect on the CT state within a donor-acceptor molecular complex of antrancene and tetracyanoquinodimethane is studied. The donor-acceptor complex and the dielectric interface are used to represent the interface between thin films consisting of these materials. We report the effect of such a dielectric interface on the energy of a CT and follow its dependence on the donor-acceptor distance. We also benchmark the anisotropy-affected energy by comparing to homogeneous dielectric calculated energies. Due to the planar interface, the anisotropic energies are expected to to match with those obtained based on isotropic calculations of the larger dielectric constant at large enough distances. The approach is applicable, in general, to more complicated dielectric constant distributions as expected to be found in actual interfaces of such thin films or in other systems, for example, for CT processes within photosystems.

中文翻译：

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各向异性介电筛选范围分离的混合密度泛函理论 跨蒽-TCNQ 供体-受体界面的电荷转移态计算。


开发了一个密度泛函理论框架来研究受各向异性介电环境影响的电子激发态。特别是，定义了一个各向异性介电筛选范围分离混合 （SRSH[r]） 泛函，并与通过广义泊松方程求解器实现的各向异性极化可连续谱模型 （PCM） 相结合。我们开发了 SRSH-PCM（r） 方法，并使用它来量化各向异性对激发电荷转移 （CT） 状态能量的影响。特别是，研究了蒽和四氰基喹啉二甲烷的供体-受体分子复合物内 CT 状态的介电界面效应。供体-受体复合物和介电界面用于表示由这些材料组成的薄膜之间的界面。我们报告了这种介电界面对 CT 能量的影响，并跟踪它对供体-受体距离的依赖性。我们还通过与均匀电介质计算能量进行比较，对受各向异性影响的能量进行基准测试。由于平面界面，各向异性能量应与在足够大的距离下基于较大介电常数的各向同性计算获得的能量相匹配。一般来说，该方法适用于更复杂的介电常数分布，如预期在此类薄膜的实际界面或其他系统中发现的那样，例如，对于光系统内的 CT 过程。