The Geometric theory of fields from Ulrich Bruchholz goes from source-free Einstein-Maxwell equations. These tensor equations involve a Riemannian geometry of the space-time. Gravitation and electromagnetism are unified this way.
As for the quantum phenomena, Ulrich tries to test it with numerical simulations according to the Einstein-Maxwell equations. The particle quantities like mass, spin, charge, magnetical momentum are integration constants in that, and are inserted as parameters into the initial conditions. As well, the number of iterations during the computation up to terminating the actual test means a degree of stability of the solution, and is marked in the graphs as more or less fat "point".
In tests only with mass and charge (remaining parameters zero), masses of preferably small nuclei significantly show, together with the right charge at the Helium nucleus, fig.1.
Unfortunately, the procedure is too inaccurate for the electron mass. In return, the other parameters show very significantly, fig.2.