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create_atoms command

Syntax:

create_atoms type keyword values ... 

Examples:

create_atoms 1
create_atoms 3 region regsphere
create_atoms 1 basis 2 5 

Description:

This command creates atoms on a lattice as an alternative to reading in their coordinates via a read_data or read_restart command. A simulation box must already exist, which is typically created via the create_box command.

Before using this command, a lattice must be defined using the lattice command. If a region is not specified, the create_atoms command fills the entire simulation box with atoms on the lattice. If a region is specified (see the region command), then the geometric volume is filled that is inside the simulation box and is also consistent with the region volume. Note that a region can be specified so that its "volume" is either inside or outside a geometric boundary.

The lattice command specifies one or more basis atoms in each unit cell. By default, when created, all basis atoms are assigned the argument type as their atom type. The keyword basis can be used to override the default for one or more basis atoms and assign them a different atom type.

By using the create_atoms command multiple times (interleaved with lattice commands specifying different orientations), grain boundaries can be created. Using the create_atoms command in conjunction with the delete_atoms command, reasonably complex geometries can be created. The create_atoms command can also be used to add atoms to a system previously read in from a data or restart file. In all these cases, care should be taken to insure that new atoms do not overlap existing atoms inappropriately.

Created atoms are assigned a velocity of 0.0.

Restrictions:

An atom_style and lattice must be previously defined to use this command.

Related commands:

lattice, region, create_box, read_data, read_restart

Default: none