Resolve "Follow-up from "Resolve "Additional AMML properties needed for oxycat use case"""

Closes #175 (closed)

docs/amml.md

@@ -373,7 +373,7 @@ transition_state      | Boolean         | None              | `true` if geometry
 energy                | Float           | [eV]              | total energy without nuclear kinetic energy; if the structure has been modified by the [algorithm](#algorithm) or [calculator](#calculator) then this is the energy of the final structure 
 forces                | FloatArray      | [eV / angstrom]   | the forces for each atom, i.e. the first derivative of energy with a minus sign; if the structure has been modified by the [algorithm](#algorithm) or [calculator](#calculator) then these are the forces in the final structure
 dipole                | FloatArray      | [elementary_charge * angstrom] | the total  electrostatic dipole moment; if the structure has been modified by the [algorithm](#algorithm) or [calculator](#calculator) then this is the dipole moment of the final structure
-vibrational_energies  | Series(Float)   | [eV]              | the eigenvalues (frequencies) of the harmonic normal modes; available only with a [calculator](#calculator) with task *normal modes*
+vibrational_energies  | Series(Float)   | [eV]              | the real eigenvalues (frequencies) of the harmonic normal modes; available only with a [calculator](#calculator) with task *normal modes*
 
 After initializing a variable with a `Property` parameter, the individual properties can be accessed using subscripting.