Pople Style Basis Sets for the Calculation of NMR Spin-Spin Coupling Constants: the 6-31G-J and 6-311G-J Basis Sets.

ABSTRACT:WepresentamodificationofthesmallandpopularPoplebasissets,6-31Gand6-311G,fordensityfunctionaltheorycalculations of Fermi contact dominated NMR indirect nuclear spin spin coupling constants. These new basis sets, 6-31G-J and6-311G-J, contain twice the number of contracted s-type functions but the same number of contracted p-type functions as theoriginalPoplebasisset.Forourtestsetof12one-,two-andthree-bondcouplingconstants,thenewbasissetsaugmentedwiththestandarddiffuseandpolarizationfunctions,i.e.,the6-31+G*-Jand6-311++G**-Jbasissets,leadtoamaximumdeviationof5and2Hz, respectively, compared to results obtained with the 6 or more times larger aug-pcJ-4 basis set. In correlated wave functioncalculations using the second-order polarization propagator approximation, the deviations with respect to the aug-ccJ-pVQZ basisset are 8 and 3 Hz and thus slightly larger.1. INTRODUCTIONIt is well-known, that standard one-electron Gaussian basissetsareingeneralnotsuitedforthecalculationofNMRindirectnuclear spin spin coupling constants (SSCC), while basis setsspecially optimized for SSCCs are often too large for routinecalculationsonlargerorganicorbiologicalmolecules.