Deuteron magnetic resonance studies. Part 4.—Dependence of some one electron properties of the ammonium ion on internuclear distance

Abstract

A series of LCAO—MO—SCF wavefunctions has been generated for the ammonium ion using a basis set of atomic SCF orbitals. The nitrogen-hydrogen bond length has been varied from 1.8 a.u. to 2.0 a.u. and the orbital exponent on the proton from 1.5 to 1.7. Deuteron quadrupole coupling constants have been calculated; these are larger than the experimental values at the observed internuclear distance by 30 %, but exhibit a strong dependence on the N—H distance. The energies, average diamagnetic shielding of the proton, and the expectation value of 〈r²_N〉 are also presented.