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Quick Start

The fastest path from a built executable to confirming it runs. Minimal explanation by design — if you want to understand why each choice is made, see First Simulation instead.

Run a minimal test

Use an already validated \(512^3\)-equivalent zoom IC and the intended parameter file, then perform a short MPI startup test:

mpirun -np 4 ./CosmicGrain parameterfile.txt

The complete IC suite should already have passed validate_music2_ic_suite.py; do not rescan all 48 large files merely as part of each startup smoke test.

Confirming success

Within the first few timesteps you should see:

  • successful HDF5 loading with seven particle types;
  • the expected cosmology and initial redshift;
  • a [DUST_FLAGS] line matching the parameter file;
  • successful domain decomposition and gravity-tree construction; and
  • no missing-parameter, non-finite-value, or particle-ID errors.

Stop the smoke test after the first few synchronized steps if it was launched only to verify startup. Do not treat a successful startup as an end-to-end physics validation.