Hydrides as Isoelectronic Perturbations of the Neon Atom
The second-row hydrides: hydrogen fluoride , water , ammonia and methane are isoelectronic with the Ne atom. The electronic structures for these 10-electron systems can be obtained, in concept, by perturbations on the Ne atom, in which protons are embedded in the electron cloud, while the central nuclear charge is reduced appropriately.[more]
The electronic structure of the molecule is represented using density functional theory, as described in . You can attempt to minimize the energy by varying the shielding parameters , and the bond distance . The results will, of necessity, be approximate, owing to the limitation in the density function . Computed Hartree–Fock energies and experimental bond distance are shown for comparison. Minimization with respect to is especially delicate, so do not expect an accurate result for the bond distance.[less]
The 10-electron density function is approximated by
following . The resulting density functional contains the usual forms for kinetic and potential energies, plus the additional contributions from the hydrogen atoms in , , and .
Experimental values of parameters: : ; : , ; : , ; : , . Approximate Hartree–Fock energies (hartrees): : , : , , : , : .
 S. M. Blinder. "Density Functional Computations on Noble Gas Atoms" from the Wolfram Demonstrations Project—A Wolfram Web Resource. demonstrations.wolfram.com/DensityFunctionalComputationsOnNobleGasAtoms.