The utility program NMR computes NMR chemical shifts. It has been developed in the Theoretical Chemistry group of the University of Calgary [5,7,11,12].
NMR requires an ASCII input file and a TAPE21 result file from an ADF calculation on the molecule to be analyzed. The ADF result file must be present with name TAPE21 in the directory where you execute NMR.
A few sample runs are contained in the ADF distribution package. See the Examples document.
Spin-orbit coupling
NMR calculations on systems computed by ADF with Spin Orbit relativistic effects included must have used NOSYM symmetry in the ADF calculation. NMR can also be combined with ADF ZORA calculations. The NMR program reads from TAPE21 the relativistic option that is used in the ADF calculation, and will use the same relativistic option in the NMR calculations.
SAOP, TAPE10
Important (ADF2004.01 or later): use SAVE TAPE10 in the ADF calculation for special exchange-correlation potentials like SIC or SAOP, since the NMR program does not know how to calculate SIC, SAOP, or other model potentials. On TAPE10 the SCF potential is written, which is read in by the NMR program.
The use of the model SAOP potential leads to isotropic chemical shifts which are substantially improved over both LDA and GGA functionals, and of similar accuracy as results with a self-interaction-corrected functional (SIC), see [21]. SAOP is computationally expedient and routinely applicable to all systems, requiring virtually the same computational effort as LDA and GGA calculations.
NICS
The Nucleus-Independent Chemical Shift (NICS) can be calculated at any point in the molecule.
Hybrids
Starting from ADF2009.01 Hartree-Fock and the hybrid potentials can used in combination with NMR chemical shielding calculations, see Refs. [22,23].
Bug fix ADF2005.01 off-diagonal part shielding tensor
Bug fix off-diagonal part shielding tensor: In the ADF2005.01 the bugs in the NMR module are fixed that gave problems in the ADF2004.01 and older versions.
