Individual gauges for localized molecular

Schindler (1987 b) tried to use IGLO correlation effects (IGLO = individual gauge for localized molecular orbitals) to calculate the magnetic susceptibility and NMR chemical shifts of N-containing compounds. For NN multiple bonds, however, the results were not satisfactory. 

IGLO Individual Gauges for Localized Molecular Orbitals... 

In this study we have presented the first simulations of solid state NMR spectra of polymers that are based on ab initio quantum chemistry. By combining statistical conformational models, empirical force-field optimization of geometries, and the Individual Gauges for Localized Molecular Orbitals (IGLO) method for the calculation of the chemical shift, it is possible to reproduce the shape and the width of the experimental solid state NMR spectra. 

Magnetic susceptibility tensors were calculated by the ab initio IGLO (individual gauge for localized molecular orbitals) method with a large basis set. The calculations showed... 

For the calculations of the shielding tensor using the Individual Gauge for Localized Orbitals (IGLO) method, the occupied MO s were localized by the method of Foster and Boys [81]. Unless noted otherwise, we use the experimental molecular geometries [82]. 

The localization procedure follows the prescription of Boys [46, 47, 48, 49] and leads to Localized Molecular Orbitals (LMO) cpi that bear physical meaning. These orbitals are centered around nuclei or bonds and are thus easily interpreted in the way of textbook chemistry. The essence of the IGLO method is the choice of an Individual Gauge for (each) Localized Molecular Orbital, which explains the abbreviation. The gauge origin R is set to the centre of charge of every LMO independently. Additionally, the stationarity of the so-... 

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