The compute keyword

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Purpose

This keyword is used to compute and output space and time averaged quantities.

Grammar

  • It is used in the following way:
   compute grouping_method sample_interval output_interval quantity_1 quantity_2 ...
  • The first parameter grouping_method refers to the grouping method defined in xyz.in. This parameter should be an integer (currently only 0, 1, or 2) and a number [math]m[/math] means the [math]m[/math]-th grouping method (we count starting from 0) in xyz.in.
  • The second parameter sample_interval means sampling the quantities every so many time steps.
  • The third parameter output_interval means averaging over so many sampled data before giving one output.
  • Starting from the fourth parameter, one can list the quantities to be computed.
  • The allowed names for the quantities are:
    • temperature, which is the temperature
    • potential, which is the potential energy
    • force, which is the force vector
    • virial, which is the diagonal part of the virial
    • jp, which is the potential part of the heat current vector
    • jk, which is the kinetic part of the heat current vector
  • One can write one or more (distinct) names in any order.

Files produced by this keyword

Examples

Example 1

For example,

   compute 0 100 10 temperature

means using the 0-th grouping method defined in xyz.in, sampling temperature every 100 time steps and averaging over 10 data points before making an output. That is, there is only one output every [math]100 \times 10=1000[/math] time steps.

Caveats

Related keywords