    Convert an xyz format file (cartesian Angstrom) to JDFTx ionpos (cartesian Bohrs).

   Usage: xyzToIonpos <xyzFile> [<centerBbox>=yes|no]

NOTE: be sure to include command "coords-type cartesian" in the input file!

Additionally, the maximum extents in each dimension will be output to stderr,
to guide the selection of supercell dimensions.

Optionally, if centerBbox=yes, the atoms will be shifted so that their bounding
box is centered on the origin (convenient when using coulomb-truncation-embed)