A matrical nodal expansion making use of temperature-dependent Kramers potentials for the Coulomb interactions, is used to compute G = F + pV in the centre of the sun. Small but, crucial quantum corrections in [MATH] and 4πρ3ee are taken into account quantitatively in the weakly coupled hydrogenic phase. The system e-p-Fe26+ is shown to be stable for small iron concentrations ≈ 10-6-10-4