Page 218 - Strategies and Applications in Quantum Chemistry From Molecular Astrophysics to Molecular Engineer

FSGO HARTREE-FOCK INSTABILITIES OF HYDROGEN 201

For intermediate values of F, either four or two values satisfy the equation. This
corresponds to one or two energy minima, respectively, both of which are unstable when
F increases. When broken symmetry solutions are observed in the absence of external
electric field one might expect a single minimum appearing either at nucleus a
or b, by turning on the electric field. In fact, for the minimum eventually appears
only at the nucleus a, because the values for its left hand side (at the nucleus a)
negative branch are slightly smaller than for its right hand side (at the nucleus b) positive
branch. Both instabilities (with respect to F) should however be extremely close one to
another. A more precise numerical analysis confirms also the possibility of two minima