Mt. Nguyen et al., EFFICIENT CALCULATION OF ISOTROPIC HYPERFINE CONSTANTS OF PHOSPHORUS RADICALS USING DENSITY-FUNCTIONAL THEORY, The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, 101(17), 1997, pp. 3174-3181
Calculations of the isotropic hyperfine coupling constants of phosphor
us nuclei in different environments have been carried out using densit
y functional theory with both B3LYP and B3PW91 functionals and a varie
ty of one-electron basis sets. A set of 35 radicals, radical cations,
and tripler species containing P have been analyzed, including the set
recently examined by Cramer and Lim (J. Phys. Chem. 1994, 98, 5024) u
sing the UMP2 method. The dependency of the calculated spin densities
with respect to the methods, basis sets, and geometries have been inve
stigated. Overall, the B3LYP method, in conjunction with a TZVP basis
optimized for DFT calculations and further augmented by right 1s-funct
ions on all heavy atoms, appears to be the most efficient treatment, p
resumably owing to better cancelations of intrinsic errors. Depending
on the size of the species examined and/or the spin contamination of U
HF references, use of UMP2 geomelries is preferred, otherwise B3LYP/6-
311G(d,p) geometries are a reasonable choice. In both cases, linear co
rrelation between computed and observed values have been found with sl
opes close to unity and small intercepts less than or equal to 10 G.