The ultraviolet-visible light (UV-vis) absorption spectrum of ferrocene is modeled with time-dependent density functional theory employing LSDA, BLYP, B3LYP, and CAM-B3LYP functionals in combination with 6-31G*, 6-31+G*, CC-PVTZ, and aug-CC-PVTZ basis sets. With the exception of LSDA, all functionals predict a reasonable Fe-CP distance of ∼1.67 Å. Diffuse functions are essential for the strongl...

We have examined the performance of semiempirical quantum mechanical methods in solving the problem of accurately predicting protein-ligand binding energies and geometries. Firstly, AM1 and PM3 geometries and binding enthalpies between small molecules that simulate typical ligand-protein interactions were compared with high level quantum mechanical techniques that include electronic correlation...

A combined computational and (13)C NMR study was used to investigate the formation of mixed aggregates of 1-methoxyallenyllithium and lithium chloride in tetrahydrofuran (THF) solution. The observed and calculated chemical shifts, as well as the calculated free energies of mixed aggregate formation (MP2/6-31+G(d)), are consistent with the formation of a mixed dimer as the major species in solut...

A new synchrotron-based photoionization spectrum of 6,6-dimethylfulvene shows significant vibrational fine structure (VFS), in contrast to previous studies; this was successfully analysed by Franck-Condon (FC) methods. The sequence ionic states the range 7 19 eV has been determined both symmetry adapted cluster configuration interaction and density functional methods, especially using long-rang...

The Dopamine has been studied theoretically at the B3LYP/6-31G* level were performed in gasphase. We calculated physical parameters like atomic charges, energy (=>), asymmetry parameter(?), chemical shift @iso, dipole moment and isotropic NMR determinant and in this work we usedGaussian 03 at NMR and calculation by using B3LYP methods with 6-31G* basis set.

In this paper,N-(2-Fluorophenyl)-2,6-dimethyl-1,3-dioxan-4-amine (C12H16FNO2) optimized geometries and frequencies of the stationary point and energies in the ground state using DFT (B3LYP) methods with 6-311Gbasis set. The calculated HOMO and LUMO energies also confirmed that the charge transfer occurred within the molecule. Bond length and bond angles values forC12H16FNO2 were calculated by u...

In the current work, chemical reactivity of some trivalent phosphorus derivatives R2PR? towards polyhaloalkanes CCl3POR ? ?2 was studied by quantum method DFT/B3LYP/6-311G(d,p). The introduction substituents for derivative and polyhaloalkane allowed us to have more information on these reactions. On one hand, calculation indices derived from DFT/B3LYP/6-311G(d,p) gapLUMO ? HOMO show that organo...

In the present work we investigate the adequacy of broken-symmetry unrestricted density functional theory for constructing the potential energy curve of nickel dimer and nickel hydride, as a model for larger bare and hydrogenated nickel cluster calculations. We use three hybrid functionals: the popular B3LYP, Becke's newest optimized functional Becke98, and the simple FSLYP functional (50% Hart...