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diffusion/multiphase command

Syntax:

diffusion/multiphase keyword args 

Examples:

diffusion/multiphase pin 1
diffusion/multiphase phase 2
diffusion/multiphase phase 3
diffusion/multiphase weight 0.5 pair 2 3 

Description:

This is an optional command used with the app_style diffusion/multiphase application.

The command is typically used multiple times, each time with one of 3 keywords.

The phase keyword defines a phase with an integer phase label.

The pin keyword also defines a phase with an integer phase label and pins the phase, so that its sites never change values due to swaps in the diffusion application. I.e. the sites in a pinned phase do not diffuse. At most one phase can be pinned.

The contribution of the energy of a pinned site to the total system energy does not change over time. However, pinned sites do contribute to the energy of neighboring sites in the usual way.

The weight keyword specifes pairwise bond energy weights between phases. The default for all weights is 1.0. A weight that is specified for an I,J pair will also be applied to J,I.

In the 4 example lines above, 3 phases are defined. Phase 1 is pinned, phases 2 and 3 are not. A weight of 0.5 is applied to the 2,3 pair of phases. The weights for the 1,2 and 1,3 pairing are the default values of 1.0.

Restrictions:

This command can only be used with the app_style diffusion/multiphase application.

Related commands:

app_style diffusion/multiphase

Default:

No phases defined, weights are all 1.0.