Gauge-invariant atomic orbitals GIAOs

In practice, calculations of xHF are based on the uncoupled Hartree-Fock, the finite field, and the self-consistent perturbation methods. Some workers use gauge-invariant atomic orbitals (GIAOs). A full review of the gauge invariance of SCF wavefunctions has been given by Epstein. 6... 

A basic defect of this type of theory is that it does not give a correct description of an isolated atom in a magnetic field. To remedy this, we follow London49 and write each molecular orbital as a linear combination of gauge-invariant atomic orbitals (GIAO) x >,... 

For the NMR chemical shieldings of four polymers, the chemical shielding tensors were calculated in the coupled perturbed Hartree-Fock (CPHF) method with the gauge-invariant atomic orbital (GIAO) [10], The calculated chemical shift for is defined by... 

The Fermi Contact Coupling Mechanism Gauge-Invariant Atomic Orbitals (GIAOs) (4<1))... 

Despite this property, the London orbitals are also known as gauge-invariant atomic orbitals (GIAOs). 

Galilean transformation, 110-113,120 gap of band, 523, 527 Gauge Invariant Atomic Orbitals (GIAO), 785-786... 

Speiss used ab initio methods (HF/6-31G ) and the gauge-invariant atomic orbital (GIAO) approach to generate NMR chemical shifts to unravel the behavior of a naphthylene-bridged molecular tweezer and a 1,4-dicyanobenzene guest. The benefit of augmenting experimental NMR data (in the solid-state and solution phase), and the X-ray structure of a 1 1 complex, with computational methods was clear to the authors who stated the following ... 

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