Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Coupled perturbed Hartree-Fock GIAO

The particular calculation considered in this tutorial was carried out using the coupled perturbed Hartree-Fock GIAO method with the 6-311G(d,p) basis. Because many of the structures we have studied have unknown experimental geometries, optimized geometries from energy minimization calculations were generally used such is the case in this example. [Pg.225]

Table 2 Computed Shielding Data (ppm) for One of the (Equivalent) Doubly Bonded Carbons in Cyclopropene Using a Coupled Perturbed Hartree—Fock GIAO Approach with a 6-311G(d,p) Basis... Table 2 Computed Shielding Data (ppm) for One of the (Equivalent) Doubly Bonded Carbons in Cyclopropene Using a Coupled Perturbed Hartree—Fock GIAO Approach with a 6-311G(d,p) Basis...
The first derivative of the density matrix with respect to the magnetic induction (dPfiv/dBi) is obtained by solving the coupled-perturbed Hartree-Fock (or Kohn-Sham) equations to which the first derivative of the effective Fock (or Kohn-Sham) operator with respect to the magnetic induction contributes. Due to the use of GIAOs, specific corrections arising from the effective operator Hcnv describing the environment effects will appear. We refer to Ref. [28] for the PCM model and to Ref. [29] for the DPM within either a HF or DFT description of the solute molecule. [Pg.10]

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... [Pg.396]

The basic computational method is that of coupled Hartree-Fock perturbation theory (14). At present we prefer the GIAO implementation mentioned above because of its computational efficiency and ease of use, but we have previously used a common gauge-origin method as implemented in the software SYSMO (15) as well as the random-phase approximation, localized orbital (RPA LORG) approach as implemented in the software RPAC (16). [Pg.306]

Another major point in which the theoretical methods differ is the quantum chemical approach to solve the operator equation of the Hamilton operator itself. The most important schemes are Hartree-Fock self consistent field (HF-SCF), density functional theory (DFT) and multi-body second order perturbation theory (MP2). Different combinations have been established, so for instance GIAO-SCF, GlAO-DI I, (,IA()-MI>2, or DF I-IGLO. Most precise measurements on small systems were done with coupled cluster methods, as for instance GIAO-CCSDT-n. ... [Pg.61]


See other pages where Coupled perturbed Hartree-Fock GIAO is mentioned: [Pg.45]    [Pg.150]    [Pg.239]    [Pg.6]    [Pg.71]    [Pg.119]    [Pg.439]    [Pg.440]    [Pg.248]    [Pg.109]   


SEARCH



Coupled Hartree-Fock

Coupled Hartree-Fock perturbation

Coupled perturbed Hartree-Fock GIAO method

Coupled perturbed Hartree-Fock,

GIAO

© 2024 chempedia.info