from a nuclear force model, an EOS can be obtained in multiple ways (see the [@steiner:13b] for an overview discussion), including direct Hartree-Fock many-body calculations, mean field models, or phenomenological models (e.g., the liquid-drop model). Typically, the minimum of the Helmholtz free energy is sought and all thermodynamic variables are obtained from derivatives of the free energy. In most cases, EOS calculations are too time consuming to be performed during a simulation. As in the case of the electron/positron EOS, large ($\gtrsim$200MB; must be stored by each `MPI` process), densely spaced nuclear EOS tables are precomputed and simulations efficiently interpolate in $(\log \rho,
      \log T, Y_e)$ to obtain thermodynamic and compositional information.

![Multi-physics modules of core-collapse supernova simulation codes. The simulation framework provides parallelization, I/O, execution scheduling, AMR, and memory management.[]{data-label="fig:components"}](f5.pdf){width="\columnwidth"}

Effects of Multidimensionality
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Stars are, at zeroth order, gas spheres. It is thus natural to start with assuming spherical symmetry in simulations – in particular given the very limited compute power available to the pioneers of supernova simulations. After decades of work, it appears now clear that detailed spherically symmetric simulations robustly fail at producing explosions for stars that are observed to explode in nature. Spherical symmetry itself 