B3LYP calculations quantum chemistry

Cl (types of calculations with correlation), we refer to DFT calculations as B3LYP. For a more complete discussion of functions, functionals, and DFT see any recent text on quantum chemistry (e.g., Levine, reading list). 

Table 3 Comparison of anharmonic frequencies (in cm-1) for the target modes of the AT-(H20)2 model structures of different two-dimensional calculations and different levels of quantum chemistry (DFT full DFT/B3LYP, 6-31++G(d,p) PM3 full PM3 DUAL DFT one-mode and PM3 two-mode PES).

Based upon the basis set dependence of conformational energies in nitramide and DMNA, we estimate the uncertainties in the conformational energies of HMX from the B3LYP/6-31 lG //MP2/6-311G quantum chemistry calculations to be around 1 kcal/mol. 

Over the decade 1995-2005, ab initio quantum chemistry has become an important tool in studying imidazole derivatives. Two highly productive approaches are often utilized for the calculations the wave function-based methods (e.g., Hartree-Fock theory and second-order Moller-Plesset perturbation theory (MP2)) and the density functional theory (DFT) based methods (e.g., gradient-corrected (BLYP) and hybrid (B3LYP) methods). 

The B3LYP hybrid functional (Becke 1993), the first hybrid functional, is the most frequently used functional (or method) in all functionals (or all theories) in quantum chemistry calculations. This functional uses three parameters as the mixing ratios to form the adiabatic connections between the Hartree-Fock exchange integral and the LDA exchange functional and between the LYP-GGA correlation functional and the LDA correlation functional, and to combine with the attenuated GGA term of the B88 exchange functional. 

As a main conclusion of these calculations we note the consistency between B3LYP and GGA+U results. This means that LCAO calculations with hybrid functionals can play the same role in quantum chemistry of solids as DFT+U and SIC DFT calculations in solid-state physics. 

The molecular geometry and spectroscopic properties of 11-ketoprogester-one have been obtained by the FIF, PM3 and DFT with the B3LYP functionals and 6-31G(d,p) basis set. The molecular dynamics study by solid-state H NMR confirmed the sequence of onset of reorientations of subsequent methyl groups, indicated by the results of quantum chemistry calculations and INS spectra. 

A wholly different picture emerges when traditional bound-state quantum chemistry methods are applied, as shown in Figure 32(b).A B3LYP/6-31-l-G calculation of the C—O moiety affords anion potential energy curves that... 

Phosphonates and their derivatives have also featured in quantum chemistry studies during 2011. A DFT study at the B3LYP/6-31G level was performed for the corrosion inhibition mechanism of methylene phosphonic acid, and DFT calculations at the B3LYP/6-311-M-G level have supported the vibrational (IR, Raman and SERS) spectroscopy characterization studies of L-leucine phosphonate analogues, and also L-valine phosphonate dipeptides. ... 

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