Towards Real Quantum Chemistry

Real Quantum Mechanics RealQM offers a model of an atom or ion as a positively charged kernel surrounded by a system of single non-overlapping electron densities interacting by Coulombic forces.  This is a classical continuum mechanics model, where the electron densities have individuality by occupying different regions of shared 3d space. RealQM is computable also for atoms with many electrons and shows good agreement with observation. 

RealQM for atoms/ions directly extends to Real Quantum Chemistry as interaction of atomic kernels surrounded by electron densities into molecules consisting of several kernels surrounded by non-overlapping electron densities. The constituents of molecules as atomic kernels and electron densities thus carry individuality, just like different material objects of continuum mechanics. 

In a world of RealQM there is thus no principal difference between physics as physics of atoms and chemistry as physics of molecules.  This not so in the world of standard Quantum Mechanics stdQM with its multidimensional wave function depending on $3N$ space coordinates for $N$ electrons, where electrons lack individuality and may overlap. This makes extension from atoms to molecules hard to realise because in the mind of a chemist, molecules occupy different regions in space with shape determining chemical properties.  

In stdQM there is thus a rift between physics of atoms without electron individuality and physics of molecules with kernel/electron individuality. Even more troubling, stdQM is uncomputable because of the high dimensionality making already the H2 molecule with two electrons into a computational challenge in six dimension, and already H2O with 10 electrons behind the capacity of any thinkable computer. 

Here you can yourself test RealQM for simple atoms/molecules by running (and inspecting) the (short) p5js-code (consisting of essentially 3 lines for updating electron densities, potentials and domains, click top name to see code and run by clicking arrow):

• H2 molecule. Compare with Two Separated H atoms. Vary kernel distance $D$ yourself.
• H2 molecule finer resolution.
• H2+ molecule (1 electron)
• Helium (2 electrons)
• Helium2 non-molecule
• Helium vs H2
• Lithium (2+1)
• Beryllium (2+2)
• Boron (2+3)
• Carbon (2+4)
• Nitrogen (2+2+3)
• Oxygen (2+4+2)
• Oxygen (2+4+2) finer resolution
• LiH molecule (2+1 + 1)
• BeH2 molecule (2+2 + 1+1)
• Boron2 molecule
• Carbon2 molecule
• Fluorine (2+4+3)
• Neon (2+4+4)
• HF molecule (2+4+3 + 1)
• CH2 molecule (2+4 + 1+1)
• CH4 molecule (2+4 + 1+1+1+1)
• CO molecule (2+4 + 2+4+2)
• H2O molecule (2+4+2 +2)
• more to come