CONGEN uses a distinct system of units, the AKMA system. I.e. Angstroms, Kilocalories / Mole, Atomic mass units. All distances are measured in Angstroms, energies in kcal/mole, mass in atomic mass units, and charge is in units of electron charge. Using this system, the AMKA unit of time is 4.888821E-14 seconds (based on the constants tabulated in Abramowitz and Stegun (1970)). 20 AKMA time units is .978 picoseconds and is sometimes referred to as a "ps".
Angles are given in degrees for the analysis and constraint sections. In parameter files, the minimum positions of angles are specified in degrees, but the force constants for angles, dihedrals, and dihedral constraints are specified in kcal/mole/radian**2. Any numbers used in the documentation may be assumed to be in AKMA units unless otherwise noted.