  A one-electron Schroedinger equation based on special one-electron potentials
for atoms is shown to exist that produces orbitals for an arbitrary molecule
that are sufficiently accurate to be used without modification to construct
single- and multi-determinant wavefunctions. The exact Hamiltonian is used to
calculate the energy variationally and to generate configuration interaction
expansions. Earlier work on equilibrium geometries is extended to larger basis
sets and molecular dissociation. For a test set of molecules representing
different bonding environments, a single set of invariant atomic potentials
gives wavefunctions with energies that deviate from configuration interaction
energies based on SCF orbitals by less than 0.04 eV per bond or valence
electron pair. On a single diagonalization of the Fock matrix, the
corresponding errors are reduced 0.01 eV. Atomization energies are also in good
agreement with CI values based on canonical SCF orbitals. Configuration
interaction applications to single bond dissociations of water and glycine, and
multiple bond dissociations of ethylene and oxygen produce dissociation energy
curves in close agreement with CI calculations based on canonical SCF orbitals
for the entire range of internuclear distances.
