Dear Wien2K users,
now I am going to calculate the NMR-Fermi contact chemical shift of Li ions in the material (with magnetic Ni ions). In the spin-polarization calculation of Wien2K. we can only obtain the hyperfine field (HFF) near the Li nucleus. In order to get the chemical shift, we need to get the hyperfine coupling constant A between Li and Ni. The equation for A is A=u0(magnetic permability)*h(planck constant)*r(nucleus gyromag ration)*g(electron g factor)*uB(Bohr magneton)*?(spin density at the nucleus)/(3S)(S is the spin quantum number of Ni)?If we obtained A, the we can get the Fermi contact chemical shift?=A*g*uB*S*(S+1)/(3*h*r*KT), where K is Boltzmann constant and T is temperature. Then the key question is to obtain the spin density at or near the neclues Li. So can we directly use the the spin density from the item "spindensities at the nucleuse(Thomson)" or the difference between spin up and spin down electron density (RUP**-RDN**)in the scf file?(I have tested this, but the calculated chemical shift seems several orders of magnitude smaller than the experiment value) Furthermore, If there are two kinds of Ni ions near the Li, the situatioin is complex. There should be two coupling constant A1 and A2 between Li and different Ni ions. Then how to get these two coupling constantn , respectively? Can we first to let one magnetic ion(for example, Ni1) to be magnetic, and force other magnetic ion to be nonmagnetic(Ni2), and get the corresponding spin density near the Li nucleus to calculate the corresponding A1 for Ni1, and do the similar process for Ni2 to obtain its coupling constant A2? I have browsed the mailing list archives and the userguide, but cannot find the answer. So I will much appreciate that if someone can help me. Best regards Zhang _________________________________________________________________ ???????????????? http://cn.bing.com/search?q=%E5%A4%A9%E6%B0%94%E9%A2%84%E6%8A%A5&form=MICHJ2 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20100421/a066ef6b/attachment.htm>