restraints harmonic <restraints-harmonic-statement> end <restraints-harmonic-statement> :== exponent=<integer> --{Exponent of the harmonic energy term. Default=2} normal=<vector> --{Normal vector of a plane. To harmonically restrain the motion of an atom to this plane set the atom property harmonic energy constant to a negative value. To turn of the planar restraints set normal=(0,0,0).} --{To setup the energy constants use the do statement.}