Theoretical study of the nitrogen atom hyperfine coupling constant
Abstract
The nitrogen atom isotropic hyperfine coupling constant A_{iso} is studied as a function of improvements in both the oneparticle and nparticle basis sets. Our study underscores the importance of diffuse basis functions. For example, the (9s 5p) primitive set of Huzinaga augmented with an eventempered diffuse s function yields values for A_{iso} that are virtually identical to an energyoptimized (23s 12p) eventempered set. The A_{iso} constant is found to converge relatively quickly with increasing l quantum numbers: d, f, and g functions are estimated to contribute 2.5±0.2, 0.4±0.1, and 0.05±0.05 MHz, respectively. Full CI calibration calculations indicate that very high levels of correlation treatment are required for quantitative results. In addition, a strong coupling is observed between the oneparticle and nparticle requirements. Our best result of 10.4 MHz is in excellent agreement with the accurate experimental value of 10.4509 MHz.
 Publication:

Journal of Chemical Physics
 Pub Date:
 September 1988
 DOI:
 10.1063/1.455004
 Bibcode:
 1988JChPh..89.2985B
 Keywords:

 Coupling Coefficients;
 Hyperfine Structure;
 Nitrogen Atoms;
 Nuclear Interactions;
 Computer Techniques;
 Convergence;
 Error Analysis;
 Set Theory;
 Wave Functions;
 Atomic and Molecular Physics