Relativistic, nearly basis-set-limit nuclear magnetic shielding constants of the rare gases He–Rn: A way to absolute nuclear magnetic resonance shielding scales

2003 ◽  
Vol 118 (7) ◽  
pp. 2973-2976 ◽  
Author(s):  
Juha Vaara ◽  
Pekka Pyykkö
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Basis Set ◽  
Magnetic Shielding ◽  
Rare Gases ◽  
Shielding Constants ◽  
Nuclear Magnetic

MP2 calculation of nuclear magnetic shielding constants involving gauge-invariant bases

1988 ◽  
Vol 66 (7) ◽  
pp. 1781-1785 ◽  
Author(s):  
Edouard C. Vauthier ◽  
Michel Comeau ◽  
Simone Odiot ◽  
Sandor Fliszar
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Spin Rotation ◽  
Basis Set ◽  
Magnetic Shielding ◽  
Resonance Spectroscopy ◽  
Correlation Effects ◽  
Gauge Invariant ◽  
Atomic Orbitals ◽  
Shielding Constants ◽  
Nuclear Magnetic

Dia- and paramagnetic shielding constants of HF, NH3, N2, H2O, and CO were calculated in the 4-31G, 4-31G*, and 6-31G** bases, using gauge-invariant atomic orbitals. Correlation effects were evaluated by 2nd-order perturbation theory: while the diamagnetic contributions are virtually unaffected by correlation, the paramagnetic parts (σρ) are modified by ~10 ppm in the 6-31G** basis. With or without correlation, calculated σρ values differ significantly from results obtained from measured spin-rotation constants. However, improvements in the basis set descriptions and inclusion of correlation yield chemical shift values for 15N and 17O converging toward their experimental counterparts obtained from conventional nuclear magnetic resonance spectroscopy.

Nuclear magnetic resonance J coupling constant polarizabilities of hydrogen peroxide: A basis set and correlation study

2012 ◽  
Vol 33 (23) ◽  
pp. 1845-1853 ◽  
Author(s):  
Hanna Kjaer ◽  
Monia R. Nielsen ◽  
Gabriel I. Pagola ◽  
Marta B. Ferraro ◽  
Paolo Lazzeretti ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Correlation Study ◽  
Basis Set ◽  
Coupling Constant ◽  
J Coupling ◽  
Nuclear Magnetic

scholarly journals Structural and Theoretical Studies of 2-amino-3-nitropyridine

2012 ◽  
Vol 9 (4) ◽  
pp. 2191-2204 ◽  
Author(s):  
N. S. Al-Hokbany ◽  
A. A. Dahya ◽  
I. Kh. Warad ◽  
N. M. Abd El-Salam ◽  
S. T. Akriche ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Single Crystal ◽  
Chemical Shifts ◽  
Vibrational Analysis ◽  
Basis Set ◽  
Geometrical Parameters ◽  
X Ray ◽  
Bond Lengths ◽  
Nuclear Magnetic

Geometrical optimization, spectroscopic analysis, electronic structure and nuclear magnetic resonance of 2-amino-3-nitropyridine (ANP) were investigated by utilizingab-initio(MP2) and DFT(B3LYP) using 6-311++G(d,p) basis set. Geometrical parameters (bond lengths, bond angles and torsion angles) were computed and compared with the experimental values obtained using X-ray single crystal measurements of the title compound. IR spectra were obtained and assigned by vibrational analysis. Comparing the theoretically calculated values (bond lengths, bond and dihedral angles) using both B3LYP/6-311++G(d,p) and MP2/6-311++G(d,p) methods of calculations with the experimentally determined data by X-ray single crystal measurements, all the data obtained in this investigation were considered to be reliable. The theoretical infrared spectra have been successfully simulated by means of DFT and MP2 levels of calculations. The1H and13C nuclear magnetic resonance (NMR) chemical shifts of 2-amino-3-nitropyridine were calculated using the GIAO method in DMSO solution using IEF-PCM model and compared with the experimental data. Intramolecular hydrogen bonding interaction in this compound was investigated by means of the NBO analysis. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule.

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