on exact Mie results, are discussed in Ref. [@RazaEtal2015JPCM].)

For the NHD model, the configuration of the nanowire is taken to be the same as that in the first test in [@HiremathEtal2012]: the radius of the cylinder is 2nm, no interband transitions are considered, the plasma frequency $\omega_p=8.65\times10^{15}$, the damping constant $\gamma=0.01\omega_p$, the Fermi velocity $v_F=1.07\times 10^{6}$, and $\beta^2=\frac{3}{5}v_F^2$. For the GNOR model, we use the same parameters and furthermore we take $D=2.04\times10^{-4}$  [@MortensenGNOR]. An artificial absorbing boundary is set to be a concentric circle with a radius of $100$nm.

As our benchmark observable we will calculate the Extinction Cross Section (ECS, $\sigma_{\text{ext}}$), which is given by the sum of the scattering cross section $\sigma_\text{sca}$ and the absorption cross section $\sigma_\text{abs}$ [@BergEtal2009], $$\sigma_\text{ext} = \sigma_\text{sca} + \sigma_\text{abs}.$$ More precisely, for the cylindrical nanowire we consider the extinction cross section per wire length, which actually has the units of a length. We scale this quantity by the diameter $2 r$ of the nanowire to obtain a dimensionless normalized extinction cross section that we denote by $\sigma_\text{ext}$. It can be expressed as the sum of scaled scattering and absorption cross sections, $$\sigma_\text{sca} = \frac{1}{2r}Re \oint_S({\mathbf{E}}^\text{sca}\times \overline{H}^\text{sca})\cdot{\mathbf{n}}\, dS, \ \text{ and } \ 