Top panels: comparison of density ρ (in code units) for a hydrodynamic, spherical blast wave at time t = 0.15. Left panel: final shock structure with an ideal EoS. Top right panel: density obtained using the H/He EoS. Alongside each panel a zoomed in view of density around the contact discontinuity is shown. The ideal EoS shows presence of Rayleigh-Taylor instability while its completely absent in case of H/He EoS. Bottom panels from left to right: comparison of 1D cuts at the mid-plane of density ρ, pressure p, temperature (T/μ) and velocity (v_x) for ideal EoS (black line) and H/He EoS (red line).