Abstract The effect of diamagnetic drifts and of long electron mean free path on the shielding of resonant magnetic perturbations by plasma rotation is investigated. The nature of the force exerted on a moving plasma by a resonant perturbation is qualitatively altered by both drift and long meanfree-path effects. The force is found to have three minima, each of which is a possible locus for dis...

Computational procedures, based on (i) the Ramsey common origin approach and (ii) the continuous transformation of the origin of the quantum mechanical current density-diamagnetic zero (CTOCD-DZ), were applied at the Hartree-Fock level to determine electric quadrupole polarizabilities of nuclear magnetic shielding for molecules in the presence of a nonuniform electric field with a uniform gradi...

The understanding and control of the magnetic properties of carbon-based materials is of fundamental relevance in applications in nano- and biosciences. Ring currents do play a basic role in those systems. In particular the inner cavities of nanotubes offer an ideal environment to investigate the magnetism of synthetic materials at the nanoscale. Here, by means of (13)C high resolution NMR of e...

A modified Freeman-Murray-Richards (FMR) correlation for the analysis of 59C0 NMR shielding parameters, 6(59C0) us. ( A V ~ , ~ ) ' / ' / A E ~ ~ , is formulated by combining the Ramsey shielding theory and the Townes and Dailey theory for the calculation of the nuclear quadrupole coupling constant. It is demonstrated that the experimental 59C0 NMR half-height linewidth is a useful parameter to...

A series of 11 oxovanadium(V) complexes mimicking the active site of vanadium haloperoxidases have been investigated by (51)V magic angle spinning NMR spectroscopy and density functional theory (DFT). The MAS spectra are dominated by the anisotropic quadrupolar and chemical shielding interactions; for these compounds, C(Q) ranges from 3 to 8 MHz, and delta(sigma) is in the range 340-730 ppm. Th...

The aromatic character of porphyrins can also be seen by NMR spectroscopy. Studies performed in the last decades demonstrated that 1H NMR spectra are very informative and adequately reflect the structural features of porphyrins.[1] The presence of the extended delocalized -electron system of the porphyrin macrocycle gives rise to a strong ring current in the molecules placed in the magnetic fi...

Pinning properties in 100nm thick continuous and porous superconducting Nb films are examined by ac susceptibility and dc magnetization measurements. The Nb filmwas deposited on a smooth Si substrate, while the porous film, NbP , was deposited on an anodized Al oxide substrate. Pores or ‘‘antidots’’ 40 nm in diameter, 100 nm apart, form a triangular array. The porous film presents commensurate ...

A new method for relativistically corrected nuclear magnetic resonance ~NMR! chemical shifts is developed by combining the individual gauge for the localized orbital approach for density functional theory with the normalized elimination of a small component using an effective potential. The new method is used for the calculation of the NMR chemical shifts of Mo and W in various molybdenum and t...