Non-Scalar Mechanical
Atomic Forces define the strength of the bonding interactions between atoms in a crystal structure away from the most stable (lowest potential energy) equilibrium configuration 1.
They are expressed as a set of vectors, one for each atom in the material, describing the combination of all inter-atomic forces acting upon it originating from all other atoms present in the crystal structure.
Atomic forces can be computed as part of any Workflow executing a total energy self-consistent field calculation.
Under the Results Tab within Jobs Viewer, the atomic forces are returned to the user as displayed in the example image below (exhibiting an ideal equilibrium situation with zero force components), expressed in units of eV/Angstroms.
The JSON schema and an example representation for this property can be found here.