4  Run a First Simulation

Start with an input file from the maintained OPALX regression suite. Those inputs are executable specifications and are checked continuously against the current parser and physics implementation.

  1. Choose a small serial regression case.
  2. Copy its .in file and required supporting files into a new working directory.
  3. Run the executable from that directory.
mpirun -np 1 /path/to/build_serial/src/opalx example.in --info 2

For a multi-GPU run, map each MPI rank to a device:

srun /path/to/build_cuda/src/opalx example.in \
  --info 2 --kokkos-map-device-id-by=mpi_rank

4.1 What to check

  • The startup banner identifies the build and execution backend.
  • Parser errors name the statement and location that could not be read.
  • Statistics and particle outputs depend on the input-file options and output commands.
  • A nonzero exit status means the run did not complete successfully.

The regression-test dashboard shows which inputs currently pass. Input-file compatibility is still being cataloged, so a regression input is safer than copying an example from the historical OPAL manual. Continue with the three complete Worked Input Files for progressively more detailed starting points.