Metal nanoparticle aggregate is an exciting platform for manipulating light-matter interactions at the nanoscale, thanks to the optically driven free electrons couple electrically across the inter-particle gap region. We use time dependent density functional theory calculations to investigate the optical response modulations in planar square-shaped aluminum nanoparticles array via morphology deformation (varying the inter-particle gap distance in the range of 2 to 20 Å) separately along one and two directions. We report the surprising observation that irrespective of the different morphology deformations, there exists an unique inter-particle gap distance of 12 Å for which, a maximum optical field enhancement can be achieved. We remark that plasmonic interaction between metal nanoparticles in an aggregate is controlled to a large extent by the size of the inter-particle gap distance. We believe that our quantum mechanical calculations will inspire and contribute to the design, control, and exploitation of aluminum based plasmonic devices.

金属纳米粒子聚集体是一个令人兴奋的平台，可在纳米级上操纵光与物质的相互作用，这要归功于光学驱动的自由电子跨粒子间的间隙区域进行电耦合。我们使用时间依赖的密度泛函理论计算来研究平面正方形铝纳米粒子阵列中沿一个方向和两个方向分别通过形态变形（在2至20范围内改变粒子间间隙距离）的光学响应调制。我们报告了令人惊讶的观察结果，即无论形态学变形如何不同，都存在一个12Å的独特粒子间间隙距离，为此，可以实现最大的光场增强。我们注意到，聚集体中金属纳米粒子之间的等离子相互作用在很大程度上受粒子间间隙距离的大小控制。我们相信，我们的量子力学计算将启发并有助于铝基等离子体激元器件的设计，控制和开发。