Indirect nuclear spin-spin couplings: *SPIN-S

 

This input module controls the calculation of which indirect nuclear spin-spin coupling constants and what contributions to the total spin-spin coupling constants that are to be calculated.

.ABUNDA  

READ (LUCMD,*) ABUND

Set the natural abundance  threshold for discarding coupling between certain nuclei. By default all isotopes in the molecule with a natural abundance above this limit will be included in the list of nuclei for which spin-spin coupling constants will be calculated. Read one more line containing the abundance threshold. The default value is 1.0, which includes both proton and C nuclides.

.NODSO  

Do not calculate diamagnetic spin-orbit  contributions to the total indirect spin-spin coupling  constants. This will give wrong results for the total spin-spin couplings.

.NOFC  

Do not calculate the Fermi contact  contribution to the total indirect spin-spin coupling  constants. This will give wrong results for the total spin-spin couplings.

.NOPSO  

Do not calculate the paramagnetic spin-orbit  contribution to the indirect spin-spin coupling  constants. This will give wrong results for the total spin-spin couplings.

.NOSD  

Do not calculate the spin-dipole  contribution to the total indirect spin-spin coupling  constants. This will give wrong results for the total spin-spin couplings.

.PRINT  

READ (LUCMD,*) ISPPRI

Set the print level in the output of the final results from the spin-spin coupling constants. In order to get all individual tensor components (in a.u.) a print level of at least 5 is needed. Read one more line containing the print level. Default value is the value of IPRDEF from the general input module.

.SD+FC  

Do not split the spin-dipole   and Fermi contact contributions in the calculations.

.SDxFC ONLY  

Will only calculate the spin dipole-Fermi   contact cross term, and the Fermi contanct-Fermi contact contribution for the triplet responses. The first of these to terms only contribute to the anistotropy, and one may in this way obtain the most important triplet contributions to the isotropic and anisotropic   spin-spin couplings by only solving one instead of ten response equations for each nucleus.

.SELECT  

READ (LUCMD,*) NPERT
READ (LUCMD, *) (IPOINT(I), I = 1, NPERT)

Select which symmetry-independent nuclei for which there is to be calculated indirect nuclear spin-spin couplings. This option will override any selection based on natural abundance (the .ABUNDA keyword), and at least one isotope of the nuclei requested will be evaluated (even though the most abundant isotope with a non-zero spin has a lower natural abundance than the abundance threshold). Read one more line containing the number of nuclei selected, and another line their number (sorted after the input order). By default, all nuclei with an isotope with non-zero spin and with a natural abundance larger than the threshold will be included in the list of nuclei for which indirect spin-spin couplings will be calculated.