boundary_conditions command
Purpose
Command for setting the boundary type (fixed/periodic) of the simulation box.
Note
This command is supported by Aspherix GPU.Syntax
boundary_conditions dimension option
One or more dimension / option pairs can be appended.
Keywords |
Description |
|---|---|
|
|
fixed (non-periodic, fixed size boundaries) or periodic (periodic fixed size boundaries)default:
fixed |
Examples
boundary_conditions x periodic
boundary_conditions x fixed y fixed z periodic
Description
Set the style of boundaries for the global simulation box in each dimension. The size of the simulation box is set by the read or the simulation_domain command.
The boundary condition can be chosen for each space dimension by using the x,
y or z keywords with the associated choice. The choice can be either ‘fixed’
or ‘periodic’. In both cases the simulation domain will have a fixed size
throughout the simulation. In the periodic case particles will interact across
the boundary and they can exit one side and re-enter on the other. The fixed
option will prevent particles from interacting across boundaries and if a
particle crosses the boundary it will be removed from the simulation.
For triclinic (non-orthogonal) simulation boxes, if the 2nd dimension of a tilt factor (e.g. y for xy) is periodic, then the periodicity is enforced with the tilt factor offset.
See the HowTo for triclinic simulations of the doc pages for a geometric description of triclinic domains, as defined by Aspherix®, and how to transform these parameters to and from other commonly used triclinic representations.
Restrictions
This command cannot be used after the simulation box is defined by a read or simulation_domain command. See the change_box command for how to change the simulation box boundaries after it has been defined.
For 2D simulations, the z-dimension must be periodic.
Default
x = fixed, y = fixed, z = fixed