fix execute command¶

Syntax¶

fix ID group-ID execute N string keyword

• ID, group-ID are documented in fix command

• execute = style name of this fix command

• N = execute every N steps

• string = text string to be executed with optional variable names

  keyword = none or once or conditional or file or start_of_step:l
  conditional value = variable name, target value, tolerance
      variable name = variable that triggers execution, needs to be defined beforehand in the input script
      target value = value of variable at which fix is executed
      tolerance = how much the value of the variable and the target value may differ

Examples¶

fix ex0 all execute 100 "variable a equal $x"
fix ex1 all execute 100 "variable a equal $x" once
fix ex2 all execute 100 "variable a equal $x" conditional trigger 10.0 0.1
fix ex3 all execute 100 "../DEM/in.subfunctions" file

Description¶

Executes a text string as LIGGGHTS command every N steps during a simulation run. This can be used for coupled simulations that would otherwise only take a given number of timesteps. If the “once” keyword is specified, the command is executed only once at time step N. The “conditional” keyword allows to specify a variable which triggers the execution of the fix if it holds the desired value. If the “file” keyword is present, LIGGGHTS looks for an input script with the name of the string to be executed. “start_of_step” executes the command at the beginning of the timestep whereas per default it is executed at the end.

Restart, fix_modify, output, run start/stop, minimize info:

No information about this fix is written to binary restart files. None of the fix_modify options are relevant to this fix. No global or per-atom quantities are stored by this fix for access by various output commands.

Restrictions¶

none

Related commands: none

Default: none