Simulation domain overview. The figure shows a slice through the x–z plane at y=0 of our tall-box setup. The box extends from −3H to +3H in the z-direction and from −0.5H to +0.5H in the x- and y-directions, where H=30.11 kpc. Periodic boundary conditions are applied in the x- and y-directions, while the z-direction features an outflow boundary condition. The simulation is conducted without CRs and assumes a target mass of m_target=22 M_⊙. The computational domain is initialised with 256×256×1536 equally spaced mesh-generating points. The left elongated panel illustrates the resulting mass density, and the right elongated panel displays the temperature. The five smaller panels provide magnified views of various structures of different sizes, shapes, densities, and temperatures formed due to TI.