Nuclear quadrupole coupling constants in NH4Cl

Abstract

Nuclear quadrupole coupling constants (NQCCs), determined from abinitio calculations of the electric field gradients at the nuclei, are discussed for NH₄Cl. We analyse the importance of correlation effects using primarily second-order Møller–Plesset perturbation theory (MP2) and the coupled clusters singles and doubles (CCSD) approximation, and discuss the dependence of the results on the basis set. We describe the variation of the results with the distances between the atoms involved in the hydrogen bond, and the NQCCs of the ¹⁴N, ³⁵Cl and ²H nuclei are found to be very sensitive probes of changes in these distances.