Vibrational and Other Corrections to the Nuclear Quadrupole Moment of 14N in Ammonia

Abstract

The field gradient at the nitrogen nucleus has been evaluated for the NH3 molecule using two different rather accurate electronic molecular wavefunctions. The vibrational correction has been obtained by averaging the field gradient for the two totally symmetric vibrations of the C3v point group computed at a number of geometrical configurations. In addition, a careful analysis has been carried out to assess the effect of the electronic quadrupole polarization and other higher order effects. The value for the nuclear quadrupole moment of 14N in ammonia so obtained is 2.16× 10−26 cm2.