DFT++ uses the following units

Energy (Hartree)

1 Hartree = 2 Rydberg = 27.2116 eV.

Length (Bohr)

1 Bohr = 0.529177 A.

Time (femto-second[fsec])

1 femto-second = 1e-15 second.
Typical optical phonon mode has period around 100 fsec.

Mass (Hartree*fsec^2/Bohr^2)

1 mass unit = 1.556907e-27 kg = 0.937591 Mass Number.
1 nucleon mass (Mass Number) = 1.6605402e-27 kg