Command warrencowley

Command: warrencowley

warrencowley computes Warren-Cowley short-range-order parameters for accepted PAIPAI states.

It writes one output file into each accepted state directory. The default output filename is struc_WC.

Basic Usage

Interstitial-metal Warren-Cowley:

warrencowley --inter-metal-cutoff 2.5

Metal-metal Warren-Cowley:

warrencowley --metal-metal-cutoff 3.0

Both:

warrencowley --inter-metal-cutoff 2.5 --metal-metal-cutoff 3.0

Use reference coordinates and occupations:

warrencowley --ref --inter-metal-cutoff 2.5

Options

Option	Default	Meaning
--root RUN_ROOT	.	Run root. By default, looks for mcprocess/ under this directory. Can also point directly to a single state directory.
--inter-metal-cutoff R	disabled (-1.0)	Compute interstitial-metal Warren-Cowley parameters using cutoff R. Must be positive to enable.
--metal-metal-cutoff R	disabled (-1.0)	Compute metal-metal Warren-Cowley parameters using cutoff R. Must be positive to enable.
-ref, --ref	false	Use reference files instead of relaxed CONTCAR.
--output FILE	struc_WC	Output filename inside each state directory. Must be relative, not absolute.
-h, --help	-	Show help.

At least one of --inter-metal-cutoff or --metal-metal-cutoff must be positive.

Coordinate Choice

By default, warrencowley uses:

SAVE + CONTCAR

That means:

• occupations come from SAVE;
• metal/interstitial coordinates are mapped from relaxed CONTCAR.

With --ref, it uses:

REFERENCE_SAVE

This computes statistics on the reference lattice rather than relaxed coordinates.

Output Labels

Interstitial-metal rows look like:

WC_B_Nb    value
WC_O_Ta    value

Metal-metal rows look like:

WC_Nb_Ta   value
WC_Ti_Hf   value

Formula

For each local environment:

alpha = 1 - P_local / c_global

where:

• P_local is the local neighbor probability within the cutoff;
• c_global is the global metal composition.

If there are no relevant centers, no neighbors, or the global concentration is zero, the output value is nan.