Generate Random Solution

OVITO Python modifier to change the particle type values to create a random solution of a given composition.

Description

Python modifier for OVITO that changes the particle types in the whole data collection or a selected subset of particles to match a user-provided target concentration. The new particle types are distributed randomly to approximate a perfect random solution. The modifier can be installed either into OVITO Pro or the OVITO Python module Python module using pip.

Parameters

• only_selected / "only selected": Apply the modifier only to the selected particles.
• concentrations / "Concentrations": List defining the target concentrations. Their sum has to be equal to 1.
• seed / "Seed": Starting value for the random number generation.

Examples

• All examples rely on fcc.lmp as input structure.

1. Example 01 loads the structure file and changes its composition from purely type 1 to a random solid solution containing 3 types with concentrations of 0.25, 0.5, and 0.25, respectively.
2. Example 02 loads the same structure file, selects all atoms with a relative position < 0.5 and changes the composition of the selected atoms from type 1 to a random solid solution containing 3 types with concentrations of 0.25, 0.5, and 0.25, respectively. The overall sample composition will not match these concentrations as the unselected region will still be of type 1.

• The following two figures show the same two examples in the OVITO Pro GUI.

Installation

• OVITO Pro integrated Python interpreter:

  ovitos -m pip install --user git+https://github.com/ovito-org/GenerateRandomSolution.git
  

  The --user option is recommended and installs the package in the user's site directory.

• Other Python interpreters or Conda environments:

  pip install git+https://github.com/ovito-org/GenerateRandomSolution.git
  

Technical information / dependencies

• Tested on OVITO 3.9.1

Contact

• Daniel Utt (utt@ovito.org)