CInt.h is the header that that should be included by external programs.
External programs should not include any other headers.

Input coordinates are in Angstroms.

INTERFACE KLUDGES

The second (comment) line in the xyz file contains the net charge
of the system.

The first line of the basis set file (gbs file) contains "spherical"
or "cartesian" to indicate the basis set type.
If no type is found, then cartesian is assumed.

The SCF initial guess for the density matrix is constructed from
the superposition of atomic densities (SAD).  The densities for 
a few atoms are read automatically from the directory containing
the basis set file.  These files are assumed be compatible with
the basis set being used.

OptErd appears hard-coded to use spherical functions.

In OptErd, primitive screening is hard-coded to True.