Question 9: Quantum Self-Assembly and Photoinduced Electron Tunneling in Photosynthetic Systems of Artificial Minimal Living Cells

Natural and artificial living cells and their substructures are self-assembling, due to electron correlation interactions among biological and water molecules, which lead to attractive dispersion forces and hydrogen bonds. Dispersion forces are weak intermolecular forces that arise from the attractive force between quantum multipoles. A hydrogen bond is a special type of quantum attractive interaction that exists between an electronegative atom and a hydrogen atom bonded to another electronegative atom; and this hydrogen atom exist in two quantum states. The best method to simulate these dispersion forces and hydrogen bonds is to perform quantum mechanical non-local density functional potential calculations of artificial minimal living cells consisting of around 1,000 atoms. The cell systems studied are based on peptide nucleic acid and are 3.0–4.2 nm in diameter. The electron tunneling and associated light absorption of the most intense transitions, as calculated by the time dependent density functional theory method, differs from spectroscopic experiments by only 0.2–0.3 nm, which is within the value of experiment errors. This agreement implies that the quantum mechanically self-assembled structures of artificial minimal living cells very closely approximate realistic ones.