Collect. Czech. Chem. Commun. 2007, 72, 64-82

The Nuclear Quadrupole Moment of 14N from Accurate Electric Field Gradient Calculations and Microwave Spectra of NP Molecule

Vladimir Kellöa,* and Andrzej J. Sadlejb

a Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-842 15 Bratislava, Slovakia
b Department of Quantum Chemistry, Institute of Chemistry, Nicolaus Copernicus University, PL-87 100 Torun, Poland


Extensive series of relativistic coupled cluster calculations of the electric field gradient at N in NP has been carried out. The accurate value of the calculated electric field gradient, combined with the highly accurate experimental value of the nuclear quadrupole coupling constant for the 14N nucleus, gives the 'molecular' value of the nuclear quadrupole moment Q(14N) = 20.46 mb. This result perfectly agrees with the value (20.44 ± 0.03 mb) determined from atomic calculations and atomic spectra. The present study involves also extensive investigations of basis sets which must be used in highly accurate calculations of electric field gradients.

Keywords: Nuclear quadrupole moment of 14N; Electric field gradients; Basis sets; Infinite-order scalar relativistic method; Coupled cluster calculations; CCSD(T); Ab initio; Gaussian.

References: 85 live references.