Syntax:
compute ID gas/collision/grid group-ID mix-ID
Examples:
compute 1 gas/collision/grid all all compute 2 gas/collision/grid subset mymixture
Description:
Count the number of gas-phase collisions bewteen pairs of particles which occur in each grid cell during the current timestep. Only gas collisions which do not result in chemical reactions are counted by this command. See the related compute gas/reaction/grid command to count collisions which induce reactions.
Only collisions within grid cells in the grid group specified by group-ID and pairs of particles with both species in the mixture specified by mix-ID are included. See the group grid command for info on how grid cells can be assigned to grid groups.
The results of this compute can be used by different commands in different ways. The values for a single timestep can be output by the dump grid command or used as inputs to the compute reduce command. The values can also be time averaged by the fix ave/grid command.
Output info:
This compute calculates a per-grid vector with the count of collisions for each grid cell.
The vector can be accessed by any command that uses per-grid values from a compute as input. See Section 6.4 for an overview of SPARTA output options.
Styles with a kk suffix are functionally the same as the corresponding style without the suffix. They have been optimized to run faster, depending on your available hardware, as discussed in the Accelerating SPARTA section of the manual. The accelerated styles take the same arguments and should produce the same results, except for different random number, round-off and precision issues.
These accelerated styles are part of the KOKKOS package. They are only enabled if SPARTA was built with that package. See the Making SPARTA section for more info.
You can specify the accelerated styles explicitly in your input script by including their suffix, or you can use the -suffix command-line switch when you invoke SPARTA, or you can use the suffix command in your input script.
See the Accelerating SPARTA section of the manual for more instructions on how to use the accelerated styles effectively.
Restrictions: none
Related commands:
compute gas/reaction/grid, compute gas/collision/tally, dump grid
Default: none