Geometry

Bond distances are given in Ångstroms (Å) and bond angles and dihedral angles in degrees (°).

Surface areas are given in (Ångstroms)2 and volumes in (Ångstroms)3.

1 Ångstrom = 1.889762 atomic units

Energies, Heats of Formation and Strain Energies

Total energies from ab initio and density functional calculations are typically given in atomic units (also termed hartrees), but are also available in kcal/mol and in kJ/mol.

Heats of formation from semi-empirical calculations are typically given in kcal/mol, but are also available in atomic units (hartrees) and in kJ/mol.

Strain energies from molecular mechanics calculations are typically given in kcal/mol, but are also available in atomic units (hartrees) and in kJ/mol.

Orbital Energies

Orbital energies from ab initio and density functional calculations are given in atomic units (hartrees).

Orbital energies from semi-empirical calculations are given in electron volts (eV).

Energy Conversions

Electron Densities, Spin Densities, Dipole Moments, Charges and Electrostatic Potentials

Electron densities and spin densities are given in electrons/(atomic units)3.

Dipole moments are given in debyes.

Atomic charges are given in electrons.

Electrostatic potentials are given in kcal/mol.

Vibrational Frequencies

Vibrational frequencies are given in wavenumbers (cm-1).