# xyz2hfc.m

Converts point electron and nuclear coordinates into a hyperfine interaction tensor.

## Syntax

    A=xyz2hfc(mxyz,exyz,isotope,nel)


## Arguments

    e_xyz    - Cartesian coordinates of the electron,
a three-element vector in Angstrom

n_xyz    - Cartesian coordinates of the nucleus,
a three-element vector in Angstrom

isotope  - isotope specification, e.g. '13C'

nel      - number of unpaired electrons


## Outputs

    A        - hyperfine coupling tensor, Gauss


## Notes

Gauss units are used for hyperfine couplings because they do not depend on the electron g-tensor.