LIGGGHTS WWW Site - LAMMPS WWW Site - LIGGGHTS Documentation - LIGGGHTS Commands

fix bond/break/gran/disk command

Syntax:

fix ID group-ID bond/break/gran/disk Nevery bondtype Rmax keyword values ... 

Examples:

fix 5 all bond/break/gran/disk 1 1 2.0 prob 0.5 49829 

Description:

This fix is part of the USER-SEAICE package; it is only enabled if LIGGGHTS was built with that package.

It breaks bonds between pairs of atoms during a simulation according to specified criteria. It is a modification of fix bond/break command (part of the MC package), modified for disk-shaped atoms with bond_style gran/disk. Once the bond is broken it will be permanently deleted.

Typically, individual bonds are broken and deleted during a simulation if their breaking criteria, specified in the bond_coeff command, are fullfilled. This command may be used if, for some reason, additional removal of bonds is required, for example to imitate sea ice melting (in which case, the breaking probability may depend on a global variable representing temperature). The parameter Rmax is an artefact of other, molecular bond types; it may be set to zero in order to remove its influence from the list of breaking criteria listed below. Note also that it is calculated as a distance between the edges of the bonded atoms, not between their centers.

A check for possible bond breakage is performed every Nevery timesteps. If two bonded atoms I,J are further than a distance Rmax of each other, if the bond is of type bondtype, and if both I and J are in the specified fix group, then I,J is labeled as a "possible" bond to break.

For details of the algorithm and the usage of this command, see the documentation of fix bond/break.


Restart, fix_modify, output, run start/stop, minimize info:

See the documentation of fix bond/break.

Restrictions:

Related commands:

atom_style hybrid disk bond/gran/disk, bond_style gran/disk, fix bond/create/gran/disk

Default:

The option defaults are prob = 1.0.

(Herman) Agnieszka Herman, Geosci. Model Devel., submitted (2015).