Real Quantum Mechanics RealQM offers a new model of *atoms* and *atomic nuclei* in the form of a *classical 3d continuum system of partial differential equations *describing a set of *non-overlapping charge densities interacting through Coulomb potentials.* This is a *generalisation of Schrödinger's equation for the Hydrogen atom* consisting of one proton and one electron, to configurations with many protons and electrons, which is different from the *multi-dimensional Schrödinger equation in configuration space *as the basic model of *standard Quantum Mechanics stdQM.*

RealQM models an atom as a point-like *nucleus/kernel* of positive charge $+Z$ surrounded by $Z$ electron densities of charge -1 organised in shells with the innermost shell containing 2 electrons, the next shell a maximum of 8 electrons, the next 18 according to the pattern $2*n^2$ for $n=1,2,...$. The shell system is formed as resolution of an energy minimisation packing problem of non-overlapping electron densities of width scaling with (inverse of) the effective kernel potential reduced by shielding from electrons in inner shells, thus with increasing width for outer shells.

RealQM models an atomic nucleus as a point-like kernel of negative charge $-Z$ surrounded in the basic case by $2*Z$ proton densities of charge +1. Only Coulomb potentials are involved. No need of strong/weak nuclear force as in the Standard Model of stdQM.

The basic difference between an atom and a nucleus both consisting of a system of protons and electrons, is then the geometric size of the system, with $10^{-10}$ m typical of an atom, and $10^{-15}$ m that of a nucleus, thus with a factor about $10^5$.

The *binding energy* of RealQM system scales with the geometric size of the system, and so we expect to pass from eV to MeV from atom to nucleus, which is what is observed and also computed by RealQM Nuclear Simulator. The basic reason is that a Coulomb potential scales with 1/distance.

RealQM thus offers an explanation of the $10^5$ factor between atomic and nuclear energies as a geometric scale effect. The basic element is here the concept of non-overlapping charge densities of different widths, which is not an element of stdQM.

As an example consider the formation of the nucleus of Deuterium from 1 electron kernel surrounded by 2 proton densities (under high pressure and temperature) as a nucleus analog of a $H^-$ ion with 1 proton kernel surrounded by 2 electron densities, under the release of 1 MeV as an analog to the formation energy of about 10 eV of $H^-$.

To form a $^4 He$ nucleus from 2 electrons surrounded by 4 proton densities, as an analog to $He^{2-}$, the two electrons have to be compressed (under high pressure and temperature) into a -2 kernel under additional release of energy to give the observed binding energy of about 7 MeV. This process remains to be explained.

The binding energy in RealQM scales with $Z^3$ with only one shell, and with $Z^2$ with a typical sequence of shells as observed, and so with $Z$ per nucleon as roughly observed for $2\le Z\le 30$, which shows release of energy under fusion (up to $^{56}Fe$):

Recall that a nucleus in the Standard Model is viewed as an aggregate of protons and neutrons held together by a strong nuclear force as new physics, while in RealQM a nucleus is considered to be an aggregate of protons and electrons held together by classical Coulomb physics. Ockham would probably choose RealQM before the Standard Model.