Syntax:
diffusion/multiphase keyword args
phase arg = ID
ID = phase label (integer)
pin arg = ID
ID = phase label (integer) for a pinned phase
weight args = w pair i j
w = weight applied between phases i and j
pair = required keyword
i,j = pair of phase labels
Examples:
diffusion/multiphase pin 1 diffusion/multiphase phase 2 diffusion/multiphase phase 3 diffusion/multiphase weight 0.5 pair 2 3
Description:
This command is used with the app_style diffusion/multiphase application.
The command is typically used multiple times, each time with one of 3 keywords.
The command must be used once for each defined phase, either with the phase keyword or the pin keyword.
The phase keyword defines a mobile phase (which can diffuse) with an integer phase label.
The pin keyword defines an immobile phase with an integer phase label. Pinned sites never exchange values with another site, i.e. the sites in a pinned phase do not diffuse.
There is no limit to the number of phases which can be defined. However there should always be two or more non-pinned phases in your model. Otherwise no diffusive exchanges between sites with different phases will take place.
The weight keyword specifies a pairwise bond energy (weight) between two neighboring sites with the specified I,J phase values. The default weight for all pairs of unlike phases is 1.0. A weight specified for an I,J pair will also be applied to J,I. Note that a weight cannot be assigned to an I,I pair; a pair of I,I neighbors do not contribute to the energy of either site.
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:
When pairwise weights are not defined, weights values default to 1.0.