The binding energy curves of SiH3-F have been investigated using nb initio valence bond seif-consistent-field (VBSCF) methods. The atomic core electrons are treated both all-electron and by using an effective core potential (ECP) representation; for comparison and testing purposes. The VB wave function is expressed in terms of the covalent (SiH3:F) and ionic (SiH3+F-, SiH3-F+) configurations, and the nonorthogonal orbitals are expanded in conventional atom-centered Gaussian basis sets. Several theory levels are applied, up to the use of different orbitals for different VB structures and allowing delocalization mixing among the passive SiH3 and F fragment orbitals. Replacing the core electrons with an ECP is found to generally have a relatively small effect on the calculated ground state bond dissociation energy (BDE) curve, but a much larger effect on the individual covalent and ionic structure energy curves. Delocalization mixing is found to be important to achieving high accuracy for the equilibrium bond distance (R-e), BDE (D-e), and dipole moment of SiH3F. The SiH3+F- ionic structure curve is found to lie below the covalent energy curve from at least R(C-F) = 1.3 Angstrom out to similar to 2.5 Angstrom, but is stable relative to the dissociation asymptote by less than half of the ground state D-e. The magnitude of D-e in SiH3-F is, therefore, determined by resonance coupling between the covalent and ionic structures (H-12), where the dominant VB structure at R-e is SiH3+F-. The SiH3:F covalent curve is found to be nearly as repulsive at its R-e value (1.59 Angstrom) as previously found for CH3:F at its R-e (1.38 Angstrom). The proportionality constant K in the equation H-12 = KS12[H-11 + H-22]/2, where H-ij and S-ij (i, j = 1, 2) are the Hamiltonian and overlap matrix elements, respectively, between the covalent and ionic configurations, has been evaluated using the results of these calculations. At the localized fragment theory level, K is found to be very close to 1 and remarkably constant over the range of R(Si-F) distances sampled here, independent of core representation and basis set.