Pipolo Silvio, Corni Stefano
Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Université Pierre et Marie Curie - Sorbonne Universités , 75005 Paris, France.
CNR Istituto Nanoscienze , 41125 Modena, Italy.
J Phys Chem C Nanomater Interfaces. 2016 Dec 22;120(50):28774-28781. doi: 10.1021/acs.jpcc.6b11084. Epub 2016 Nov 21.
The optical properties of molecules close to plasmonic nanostructures greatly differ from their isolated molecule counterparts. To theoretically investigate such systems from a quantum-chemistry perspective, one has to take into account that the plasmonic nanostructure (e.g., a metal nanoparticle-NP) is often too large to be treated atomistically. Therefore, a multiscale description, where the molecule is treated by an ab initio approach and the metal NP by a lower level description, is needed. Here we present an extension of one such multiscale model [Corni, S.; Tomasi, J. J. Chem. Phys.2001, 114, 3739], originally inspired by the polarizable continuum model, to a real-time description of the electronic dynamics of the molecule and of the NP. In particular, we adopt a time-dependent configuration interaction (TD CI) approach for the molecule, the metal NP is described as a continuous dielectric of complex shape characterized by a Drude-Lorentz dielectric function, and the molecule-NP electromagnetic coupling is treated by an equation-of-motion (EOM) extension of the quasi-static boundary element method (BEM). The model includes the effects of both the mutual molecule-NP time-dependent polarization and the modification of the probing electromagnetic field due to the plasmonic resonances of the NP. Finally, such an approach is applied to the investigation of the light absorption of a model chromophore, LiCN, in the presence of a metal-NP of complex shape.
靠近等离子体纳米结构的分子的光学性质与其孤立分子对应物有很大不同。从量子化学角度对这类系统进行理论研究时，必须考虑到等离子体纳米结构（例如金属纳米颗粒-NP）通常太大而无法进行原子级处理。因此，需要一种多尺度描述方法，其中分子采用从头算方法处理，金属NP采用较低层次的描述方法。在此，我们将一种最初受可极化连续介质模型启发的多尺度模型[科尔尼，S.；托马西，J. J. 化学物理.2001, 114, 3739]扩展到对分子和NP的电子动力学进行实时描述。具体而言，对于分子我们采用含时组态相互作用（TD CI）方法，金属NP被描述为具有复杂形状的连续介质，其特征由德鲁德-洛伦兹介电函数表示，分子-NP电磁耦合通过准静态边界元方法（BEM）的运动方程（EOM）扩展来处理。该模型包括分子-NP相互的含时极化效应以及由于NP的等离子体共振对探测电磁场的修正。最后，将这种方法应用于研究在存在复杂形状金属NP的情况下模型发色团LiCN的光吸收。
