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# fix heat/flow command

## Syntax

    fix ID group-ID heat/flow style values ...

- ID, group-ID are documented in fix command

- heat/flow = style name of this fix command

- one style with corresponding value(s) needs to be listed

      style = constant or type
        constant = cp
          cp = value of specifc heat (energy/(mass * temperature) units)
        type = cp1 ... cpN
          cpN = value of specifc heat for type N (energy/(mass * temperature) units)

## Examples

    fix 1 all heat/flow constant 1.0
    fix 1 all heat/flow type 1.0 0.5

## Description

Perform plain time integration to update temperature for atoms in the group each timestep. The specific heat of atoms can be defined using either the constant or type keywords. For style constant, the specific heat is a constant value cp for all atoms. For style type, N different values of the specific heat are defined, one for each of the N types of atoms.

## 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. No parameter of this fix can be used with the start/stop keywords of the run command. This fix is not invoked during energy minimization.

## Restrictions

This pair style is part of the GRANULAR package. It is only enabled if LAMMPS was built with that package. See the Build package page for more info.

This fix requires that atoms store temperature and heat flow as defined by the fix property/atom command.

## Related commands

pair granular, fix add/heat, fix property/atom

## Default

none