Premium
Calculation of 13 C‐NMR chemical shift using the intermediate neglect of differential overlap model
Author(s) -
Baker John David,
Zerner Michael C.
Publication year - 1992
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560430304
Subject(s) - diamagnetism , paramagnetism , chemistry , hamiltonian (control theory) , electromagnetic shielding , chemical shift , molecule , computational chemistry , shielding effect , nuclear magnetic resonance , magnetic field , physics , quantum mechanics , organic chemistry , mathematics , mathematical optimization
The local origin/local orbital ( LORG ) method of Hansen and Bouman has been implemented with the intermediate neglect of differential overlap Hamiltonian for spectroscopy ( INDO / S ). The method is shown capable of demonstrating the inductive effects associated with electron‐withdrawing substituents through the diamagnetic shielding term. In addition, the method is capable of differentiating chemical shift in differing bond environments. The calculated paramagnetic contribution, however, is deficient for substituents that saturate the minimal basis such as oxygen and fluorine, which severely limits the general utility of the procedure. Through the utilization of reduced linear equations for the paramagnetic term, the method is amenable to any molecule for which a self‐consistent field can be performed and therefore can potentially be used to study very large systems. At present, however, the LORG method when used with the rapid INDO / S model Hamiltonian does not reliably reproduce the paramagnetic contribution to the shielding.