Gaussian 03 Online ManualLast update: 13 February 2008 | |

## NMRThis properties keyword predicts NMR shielding tensors and magnetic susceptibilities using the Hartree-Fock method, all DFT methods and the MP2 method [232,234,528, 587]. NMR
shielding tensors may be computed with the Continuous Set of Gauge Transformations
(CSGT) method [231,233,235]
and the Gauge-Independent Atomic Orbital (GIAO) method [226,227,228,229,230].
Magnetic susceptibilities may also be computed with both GIAOs [236,237]
and CGST. Structures used for NMR calculations should have been optimized at a good level of theory. Note that CSGT calculations require large basis sets to achieve accurate results. Spin-spin
coupling constants may also be computed during an NMR job [238,239,240,241],
via the
SCF,
DFT and MP2 methods. In Here is an example of the default output from Magnetic properties (GIAO method) Magnetic shielding (ppm): 1 C Isotropic = 57.7345 Anisotropy = 194.4092 XX= 48.4143 YX= .0000 ZX= .0000 XY= .0000 YY= -62.5514 ZY= .0000 XZ= .0000 YZ= .0000 ZZ= 187.3406 2 H Isotropic = 23.9397 Anisotropy = 5.2745 XX= 27.3287 YX= .0000 ZX= .0000 XY= .0000 YY= 24.0670 ZY= .0000 XZ= .0000 YZ= .0000 ZZ= 20.4233 For this molecular system, the values for all of the atoms of a given type are equal, so we have truncated the output after the first two atoms. The additional output from spin-spin coupling computations appears as follows: Total nuclear spin-spin coupling K (Hz): 1 2 1 0.000000D+00 2 0.147308D+02 0.000000D+00 Total nuclear spin-spin coupling J (Hz): 1 2 1 0.000000D+00 2 0.432614D+03 0.000000D+00 The various components of the coupling constants precede this section in the output file. It displays the matrix of isotropic spin-spin coupling between pairs of atoms in lower triangular form. The K matrix gives the values which are isotope-independant, and the J matrix gives the values taking the job's specific isotopes into account (whether explicitly specifed or the default isotopes). |