# Output

### A series of vtk files created on-the-fly

The main output of a CAC simulation are cac_cg_#.vtk and cac_atom_#.vtk files that contain elemental/nodal information and atomic information in the coarse-grained and the atomistic domains, respectively, where #, a non-negative integer, is the simulation step at which the file is created. These files, created by vtk_legacy.f90 with a frequency of output_freq, can be read by ParaView. Note that besides the nodal/atomic positions, the energy scalar, the force vector, and the stress tensor of each node/atom are also recorded in these vtk files.

### One-time vtk and dump files

Besides the files that are created on-the-fly, in the beginning of a simulation, a model_atom.vtk file containing atomic positions in the atomistic domain, a model_cg.vtk file containing nodal positions in the coarse-grained domain, and a model_intpo.vtk file containing integration point positions and weights in the coarse-grained domain are also created, by vtk_legacy_model.f90. A standard LAMMPS dump file dump.lammps which, in addition to the positions of the real/interpolated atoms, also contain the velocities of the real/interpolated atoms if simulation_style = dynamics or hybrid, is created by atomp_plot_lammps.f90. When the total number of groups > 0, multiple group_cg_*.vtk and group_atom_*.vtk files, where *, a positive integer, is the group id, are created by vtk_legacy_group.f90 for the coarse-grained and the atomistic domains, respectively. These files are used to show whether the initial simulation cell and group settings are correct. Different from the cac_cg_#.vtk and cac_atom_#.vtk files, the one-time vtk files here do not contain the energy/force/stress information, but only the nodal/atomic positions.

All vtk and dump files are then post-processed for visualization purposes.

### Other files

cac.log is the log file of a CAC simulation, containing information mostly written by cac_log.f90.

stress_strain and temperature, with a frequency of log_freq, record the $3\times 3$ stress/strain tensors and the temperature, respectively, at certain simulation step.

A series of cac_out_#.restart files, where # is a positive integer, are created with a frequency of restart_freq. One of these files can then be renamed to cac_in.restart to restart a prior simulation when boolean_restart = t.

If boolean_debug = t, a writable debug file is created by debug_init.f90. The user can then write to it whatever he/she wants using unit number 13, i.e.,

write(13, format) output


When the total number of groups > 0, a series of group_out_*_#.id files are created, where * is the group id starting from 1 and # is the simulation step at which the file is created. These files can then be renamed to group_in_*.id for restart group and refinement purposes.