Top panel: non-equidistant vertical spacing Δz of the depth scale as a function of geometrical depth in our solar model (solid line). The z-scale is optimized to resolve the flows and thermal structure, which naturally results in the highest spatial resolution around the photosphere. Furthermore, we also show the maximum of the vertical gradient of the absorption coefficient max⟨dlnα_Ross/dz⟩ as a function of depth (dotted line). Bottom panel: aspect ratio Δz/Δx (solid line) and we also indicated its lower allowed limit with 1:4 (dashed line). The actual vertical-to-horizontal aspect ratio ranges from 0.26 at the photosphere to 1.18 at the bottom of the simulation domain.