6. Particle Restart File Format

The current version of the particle restart file format is 2.0.


  • filetype (char[]) – String indicating the type of file.

  • version (int[2]) – Major and minor version of the particle restart file format.

  • openmc_version (int[3]) – Major, minor, and release version number for OpenMC.

  • git_sha1 (char[40]) – Git commit SHA-1 hash.

  • current_batch (int) – The number of batches already simulated.

  • generations_per_batch (int) – Number of generations per batch.

  • current_generation (int) – The number of generations already simulated.

  • n_particles (int8_t) – Number of particles used per generation.

  • run_mode (char[]) – Run mode used, either ‘fixed source’, ‘eigenvalue’, or ‘particle restart’.

  • id (int8_t) – Unique identifier of the particle.

  • type (int) – Particle type (0=neutron, 1=photon, 2=electron, 3=positron)

  • weight (double) – Weight of the particle.

  • energy (double) – Energy of the particle in eV for continuous-energy mode, or the energy group of the particle for multi-group mode.

  • xyz (double[3]) – Position of the particle.

  • uvw (double[3]) – Direction of the particle.

  • time (double) – Time of the particle in [s].