We report the results of a benchmarking study on hybrid, hybrid-meta, long-range-corrected, meta-generalized gradient approximation (meta-GGA), and GGA density functional theory (DFT) methods for aluminum (Al) clusters. A range of DFT functionals, such as B3LYP, B1B95, PBE0, mPW1PW91, M06, M06-2X, ωB97X, ωB97XD, TPSSh, BLYP, PBE, mPWPW91, M06-L, and TPSS, have been used to optimize the molecula...

The mechanism for OH and NO3 radical-initiated oxidation reactions of methyl methacrylate (MMA) was investigated by using density functional theory (DFT) molecular orbital theory. Geometrical parameters of the reactants, intermediates, transition states, and products were fully optimized at the B3LYP/6-31G(d,p) level. Detailed oxidation pathways were presented and discussed. The rate constants ...

The structural, cohesive, electronic and optical properties of mixed SiGe:H quantum dots are studied by Density Functional Theory (DFT) calculations on a representative ensemble of medium size nanoparticles of the form SixGe47−x : H60. The calculations have been performed in the framework of the hybrid non-local exchange-correlation functional of Becke, Lee, Parr and Yang (B3LYP). Besides the g...

The effective fragment potential (EFP) method, is a discrete method for the treatment of solvent effects, originally formulated using Hartree–Fock (HF) theory. Here, a density functional theory(DFT) based implementation of the EFP method is presented for water as a solvent. In developing the DFT based EFP method for water, all molecular properties (multipole moments, polarizabilitytensors, scre...

Large-scale density functional theory calculations (DFT) found various types of binding of an unsaturated hydrocarbon (C2H2 and C2H4) to a ZSM-5 zeolite extraframework copper cation. We employed the DFT calculations based on the B3LYP functional to obtain local minima of an unsaturated hydrocarbon adsorbed on one or two copper cations embedded inside ZSM-5, and then compared their stabilization...

The performance of six frequently used density functional theory (DFT) methods (RPBE, OLYP, TPSS, B3LYP, B3LYP*, and TPSSh) in the prediction of Mössbauer isomer shifts(δ) and quadrupole splittings (ΔEQ) is studied for an extended and diverse set of Fe complexes. In addition to the influence of the applied density functional and the type of the basis set, the effect of the environment of the mo...

The technetium-99m complex of the L,L-ethylenedicysteine diethylester (EC), of the brain imaging agent, was reported as a good choice for replacement of the renal nuclear medicines like OIH radiopharmaceutical. This present research work studies the structural, electronic and spectral properties of the EC compound and its complex with technetium-99m radionuclide from theoretical insight. All co...

We report a comprehensive computational benchmarking of the structural and optical properties of a bis(chelate) copper(I) guanidine-quinoline complex. Using various (TD-)DFT flavors a strong influence of the basis set is found. Moreover, the amount of exact exchange shifts metal-to-ligand bands by 1 eV through the absorption spectrum. The BP86/6-311G(d) and B3LYP/def2-TZVP functional/basis set ...

The structure of diglycolic anhydride (1,4-dioxane-2,6-dione; DGAn) isolated in a low-temperature argon matrix at 10 K was studied by means of FTIR spectroscopy. Interpretation of the experimental vibrational spectrum was assisted by theoretical calculations at the DFT(B3LYP)/aug-cc-pVTZ level. The optimized structure of the isolated DGAn molecule adopts an envelope conformation, which was foun...