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### compute sum/atom command

Syntax:

    compute ID group-ID sum/atom compute-ID1 compute-ID2 ...

- ID, group-ID are documented in compute command
- sum/atom = style name of this compute command
- compute-ID1, 2, ... = IDs of computes that calculate per-atom quantities

Examples:

    compute 1 all sum/atom atomKE atomEpair atomEbond

Description:

Define a computation that sums the results of two or more other computes for each atom in a group. This is useful for summing atom properties such as pairwise energy, bond energy, kinetic energy, etc. The resulting values can be accessed by any command that uses per-atom computes, e.g. the dump custom command or fix ave/spatial command or fix ave/atom command.

The value of the sum will be 0.0 for atoms not in the specified compute group.

The result of this compute depends on the results generated by the other computes that it invokes. E.g. if the other computes each generate a scalar value per atom, so will this compute. If the other computes each generate a vector of values per atom, so will this compute. In the latter case, all the other computes must generate per-atom vectors of the same size.

Restrictions: none

Related commands:

compute sum

Default: none