[@Govorov2010; @Wu2015]. However, meta-atoms with complicated multipolar transitions can also be modelled into $\boldsymbol{\alpha}$-tensors, which are then inserted into the MST [@Watson2017], potentially allowing studies on more complicated physics, e.g., Fano resonances [@Gallinet2011a; @Suryadharma2019] and hybridization of particle and lattice resonances in 2D [@MahdiSalary2017; @Baur2018; @Terekhov2019; @Kwadrin2014] and 3D [@Liu2008; @Kim2017] arrays. In this section, we reconstruct several physical phenomena arising in electromagnetically coupled meta-atoms simply by implementing $\boldsymbol{\alpha}$-tensors into the MST, and discuss the advantages of this method.

![Reconstructed optically coupled systems using $\boldsymbol{\alpha}$-tensors and MST. (a,b) Plasmon-coupling between two coupled nanorods at different coupling configurations, and (c) Fano resonance between dark and bright elements. The nanorods in (a,b) are approximated as $\boldsymbol{\alpha}$-tensor with only $(\alpha_{e1}^{e1})_{x}^{x}$; the bright element in (c), as $(\alpha_{e1}^{e1})_{y}^{y}$; the dark element in (c), as $(\alpha_{e1}^{e1})_{x}^{x}$, $(\alpha_{m1}^{m1})_{z}^{z}$, $(\alpha_{m1}^{e2})_{z}^{xy}$, $(\alpha_{e2}^{m1})_{yz}^{z}$, and $(\alpha_{e2}^{e2})_{xy}^{xy}$ (see Fig. \[fig:PDB\]b). The configurations are illustrated in the schematics on the left sides. The scattering cross-sections calculated at different center-to-center distances $g$ are on the right sides. Dashed-lines and cross-marks are the reference solutions calculated using STMM and FEM, respectively. The nanorods in (a,b) and the dark element in (c) have $a$ = 10 nm and $c$ = 40 nm, and the bright 