Two columns per page - longtable*

Question

Dears, good morning.

How can I leave the following arrangement in the form of two columns per page? That is the pattern of the model I am using. The command is:

{\renewcommand\arraystretch{1.0}
\noindent\begin{longtable*}{@{}l @{\quad=\quad} l@{}}
$A$ & surface area, $\mathrm{m^{2}}$  \
$\hat{C}{p}$ & heat capacity at constant pressure, $\mathrm{J/(kg.K)}$    \
$\hat{C}{v}$ & heat capacity at constant volume, $\mathrm{J/(kg.K)}$    \
$C_{\varepsilon 1}$ & empirical constant of $\kappa-\varepsilon$ model \
$C_{\varepsilon 2}$ & empirical constant of $\kappa-\varepsilon$ model \
$C_{\mu}$ & empirical constant of $\kappa-\varepsilon$ model \
$E_{b}$ & blackbody emissive power, $\mathrm{W/m^{2}}$   \
$F_{ij}$ & view factor \
$\boldsymbol{g}$ & gravity acceleration, $\mathrm{m/s^{2}}$   \
$G$ & incident radiation or irradiation, $\mathrm{W/m^{2}}$   \
$G_{0}$ & external radiation that reaches the surface in analysis, $\mathrm{W/m^{2}}$   \
$H$ & reference physical domain height, $\mathrm{m}$  \
$I$ & intensity of radiation, $\mathrm{W/(m^{2}.sr)}$   \
${k_{t}}$ & thermal conductivity, W/(m.K)   \
$p_{-} r g h$ & absolute dynamic pseudo-pressure, $\mathrm{Pa}$ \
$P$ & absolute total pressure, $\mathrm{Pa}$    \
$\bar{P}$ & component average of pressure in the RANS model, $\mathrm{Pa}$     \
$Pr$ & Prandtl number \
$Pr_{t}$ & turbulent Prandtl number \
$q_{conv}$ & convective heat flux, $\mathrm{W/m^{2}}$  \
$q_{net}$ & net heat flux, $\mathrm{W/m^{2}}$  \
$q_{rad}$ & radiative heat flux, $\mathrm{W/m^{2}}$  \
$\bar{q}^{(v)}$ & viscous heat flux, $\mathrm{W/m^{2}}$  \
$\bar{q}^{(t)}$ & turbulent heat flux, $\mathrm{W/m^{2}}$  \
$r$ & radius, $\mathrm{m}$  \
$R$ & gas constant, $\mathrm{J/(kg.K)}$    \
$Ra_{H}$ & Rayleigh number calculated with the height as characteristic length  \
$t$ & time, $\mathrm{s}$   \
$T$ & temperature, $\mathrm{K}$     \
$\bar{T}$ & average temperature, $\mathrm{K}$     \
$\tilde{T}$ & component average of temperature in the RANS model, $\mathrm{K}$     \
$\boldsymbol{u}$ & velocity vector, $\mathrm{m/s}$     \
$\overline{u_{\imath}^{\prime} T^{\prime}}$ & turbulent fluctuations in the RANS model, $\mathrm{(m.K)/s}$\
$\bar{u}$ & average components of velocity in the RANS model, $\mathrm{m/s}$   \
$u_{}^{\prime}$ & floating components of velocity in the RANS model, $\mathrm{m/s}$   \
$U$ & velocity field OpenFOAM® parameter, $\mathrm{m/s}$  \
$\hat{U}$ & specific internal energy, $\mathrm{J/kg}$    \
$x$ & x coordinate, $\mathrm{m}$   \
$y$ & y coordinate, $\mathrm{m}$     \
$z$ & z coordinate, $\mathrm{m}$     \
$z^{*}$ & elevation, $\mathrm{m}$ \
$\alpha$ & under-relaxation factor \
$\alpha_{t}$ & turbulent thermal diffusivity, $\mathrm{m^{2}/s}$ \
$\beta$    & thermal coefficient of volume expansion, $\mathrm{K^{-1}}$ \
$\delta_{i j}$    & Kronecker’s delta function\
$\epsilon $   & emissivity \
$\varepsilon $    & dissipation rate of turbulent kinetic energy, $\mathrm{{m^{2}}/{s^{3}}}$ \
$\theta$    & polar angle, $\mathrm{rad}$ \
$\kappa$    & turbulent kinetic energy, $\mathrm{{m^{2}}/{s^{2}}}$ \
$\mu$    & dynamic viscosity, kg/(m.s)\
$\mu {t}$    & turbulence dynamic viscosity, kg/(m.s) \
$\nu$    & kinematic viscosity, $\mathrm{m^{2}/s}$ \
$\nu{t}$    & turbulence kinematic viscosity, $\mathrm{m^{2}/s}$ \
$\rho$    & fluid density, $\mathrm{kg/m^{3}}$ \
$\bar{\rho}$ & fluid density evaluated in $\bar{T}$, $\mathrm{kg/m^{3}}$ \
$\sigma_{\varepsilon}$    & empirical constant of $\kappa-\varepsilon$ model \
$\sigma_{\kappa}$    & empirical constant of $\kappa-\varepsilon$ model \
$\bar{\Phi}{v}^{(v)}$    & viscous dissipation function, $\mathrm{s^{-2}}$ \
$\bar{\Phi}{v}^{(t)}$    & turbulent energy dissipation function, $\mathrm{s^{-2}}$  \
$\Omega$    & solid angle, $\mathrm{sr}$  \
\multicolumn{2}{@{}l}{\emph{Subscripts}}\
$i$ & counter or index of summation \
$j$ & counter or index of summation \
\end{longtable*}}

The following error is pointed out on the 2nd line:

Package longtable Error: longtable not in 1-column mode. Overfull \hbox (80.39828 pt too wide) in alignment at lines 516--537

I appreciate everyone's attention and help.

Best regards.