3.6. Compute stylesΒΆ
Classes that compute scalar and vector quantities like temperature and the pressure tensor, as well as classes that compute per-atom quantities like kinetic energy and the centro-symmetry parameter are derived from the Compute class. New styles can be created to add new calculations to LAMMPS.
Compute_temp.cpp is a simple example of computing a scalar temperature. Compute_ke_atom.cpp is a simple example of computing per-atom kinetic energy.
Here is a brief description of methods you define in your new derived class. See compute.h for details.
init |
perform one time setup (required) |
init_list |
neighbor list setup, if needed (optional) |
compute_scalar |
compute a scalar quantity (optional) |
compute_vector |
compute a vector of quantities (optional) |
compute_peratom |
compute one or more quantities per atom (optional) |
compute_local |
compute one or more quantities per processor (optional) |
pack_comm |
pack a buffer with items to communicate (optional) |
unpack_comm |
unpack the buffer (optional) |
pack_reverse |
pack a buffer with items to reverse communicate (optional) |
unpack_reverse |
unpack the buffer (optional) |
remove_bias |
remove velocity bias from one atom (optional) |
remove_bias_all |
remove velocity bias from all atoms in group (optional) |
restore_bias |
restore velocity bias for one atom after remove_bias (optional) |
restore_bias_all |
same as before, but for all atoms in group (optional) |
pair_tally_callback |
callback function for tally-style computes (optional). |
memory_usage |
tally memory usage (optional) |
Tally-style computes are a special case, as their computation is done in two stages: the callback function is registered with the pair style and then called from the Pair::ev_tally() function, which is called for each pair after force and energy has been computed for this pair. Then the tallied values are retrieved with the standard compute_scalar or compute_vector or compute_peratom methods. The compute styles in the TALLY package provide examples for utilizing this mechanism.