Nuclear-magnetic-resonance (NMR) quantum-computer architectures have been by far the leading architectures in implementing small-scale proof-of-principle quantum computations. However, for an efficient computer initialization, nuclear spin polarizations of 100% are required. The low thermal nuclear-spin polarizations therefore prevent the realization of large-scale NMR quantum computers. It has...

In this research at the first Metoprolol drug and its fullerene derivative were optimized. Natural bond orbital (NBO), nuclear Indepndent chemical shift (NICS) and finally IR calculations, for these compounds were carried out at the B3LYP/6-31G* quantum chemistry level. Different parameters such as energy levels, the amount of chemical shift in different atoms, the amount of HOMO/LUMO, chemical...

sulforaphane, an isothiocyanate found in broccoli and other cruciferous vegetables. it is an antioxidantand anti-cancer agent, and reduces blood pressure, and also has anti-allergic effects.in this article, six theoretical methods have been used for calculation of physical parameters insolforaphane and several similar compounds. we calculated physical parameters like atomic charges.energy (ae) ...

Z. Naturforsch. 55 b, 459—461 (2000); received February 21, 2000 Biomineralization, Silica, Silicon-Accumulating Plants A series of silicon-accumulating plants [different Equisetum (horse tail) species, Echium vulgare, and Symphytum officinale] were studied by solid-state 29Si NMR experiments. For this purpose, selected parts of these plants were freeze-dried and then investigated by solid-stat...

Two-dimensional magic angle flipping (MAF) was employed to measure the Q(n) distribution in a 29Si enriched potassium disilicate glass (K2O · 2 SiO2). Relative concentrations of [Q(4)] = 7.2% ± 0.3%, [Q(3)] = 82.9% ± 0.1%, [Q(2)] = 9.8%± 0.6% were obtained. Using the thermodynamic model for Q(n) species disproportionation these relative concentrations yield an equilibrium constant k3 = 0.0103± ...

Indirect observation: Combination of indirect DNP, detection through 29Si, and 29Si-CPMG acquisition enabled measurements non-protonated oxygen at natural abundance.

A new NMR experiment which allows a measurement of the chemical shift anisotropy (CSA) tensor under magic angle spinning (MAS) is described. This correlates a fast MAS spectrum in the omega2 dimension with a sideband pattern in omega1 in which the intensities mimic those for a sample spinning at a fraction of the rate omega r/N, and these sidebands result from an amplification by a factor N of ...