**intratorsion** calculates a histogram of angles, from -180 to +180, for a single torsion angle in a given species.

Related programs:

- To calculate a torsion angle formed between two species, see
**intertorsion**.
- To calculate a torsion angle map between two torsions, see
**intratorsion2**.
- To calculate average geometry parameters (not histograms), see
**geom**.

## Basic Usage

`intratorsion <HISTORYfile> <OUTPUTfile> <sp> <i> <j> <k> <l>`

Where:

`<HISTORYfile>`

is the name of the DL_POLY HISTORY file
`<OUTPUTfile>`

is the name of the DL_POLY OUTPUT file
`<sp>`

is the integer index of the target species
`<i>`

is the integer index of the atom 'i' in the torsion i-j-k-l
`<j>`

is the integer index of the atom 'j' in the torsion i-j-k-l
`<k>`

is the integer index of the atom 'k' in the torsion i-j-k-l
`<l>`

is the integer index of the atom 'l' in the torsion i-j-k-l

## Switches

None.

## Output Files

The torsion angle histogram is written to a file named after the input + `<HISTORYfile>`

, ending with `<i>-<j>-<k>-<l>.tors`

.