A theoretical study of the beryllium bonds in BeR2:C6X6 (R = H, F, Cl and X = H and F) has been carried out by means of MP2/aug'-cc-pVDZ computational methods. In addition, the ternary complexes BeR2:C6X6:Y- (Y = Cl and Br) have been analyzed. Geometric, energetic and electronic aspects of the complexes have been taken into account. All the parameters analyzed provide a clear indication of favo...

The ab initio scalar ZORA approach, which was previously tested within the context of numerical and basis set SCF calculations, is generalized to include electron correlation. The technical details of the method are investigated in calculations on the systems Ne2, Ar2, Kr2 and Xe2. For the weakly bonded rare gas dimers we calculated the bond lengths and well depths using the non-relativistic ZO...

The HF/3s2pld and MP213s2pld structures, energies and vibrational frequencies were calculated for ten N8 isomers, corresponding to ten analogous CH structures. Comparative calculations using density functional theory (DFT), with a cc-pVTZ basis set, were also performed. All ten structures were found to be local minima on the energy hypersurface at the Hartree-Fock (HF) level, whereas at the sec...

Ab initio MP2/aug’-cc-pVTZ calculations have been carried out to determine the structures and binding energies of complexes BeF2, BeF3–1, BeF4–2 with n H2O molecules, n = 1–6. For each ...

The interaction of a water molecule with the (100) surface of MgO as described by cluster models is studied using MP2, coupled MP2 (MP2C) and symmetry-adapted perturbation theory (SAPT) methods. In addition, diffusion Monte Carlo (DMC) results are presented for several slab models as well as for the smallest, 2X2 cluster model. For the 2X2 model it is found that the MP2C, DMC, and CCSD(T) metho...

the methamphetamine has been studied theoretically at the mp2 [1]/6-31g[2] level in gas phase.methamphetamine has been investigated via nmr, frequencies calculation and nbo analysis. thestructure of methamphetamine was designed primarily using of chem. bio draw and it geometry hasbeen optimized at the mp2/6-31g computational level. the present work consists the study of themethamphetamine repor...

Predictions of the BLYP density functional are compared with wavefunction-based calculations for several structural and Ž . q dynamical properties of H O H . We focus attention on properties important for proton transfer in this cluster. Good 2 3 Ž . agreement between density functional theory DFT calculations and all-electron MP2 results is found for energies, structures, and vibrational prope...

This paper presents MarkPledge3 (MP3), the most efficient specification of the MarkPledge (MP) technique. The MP technique allows the voter to verify that her vote is correctly encrypted with a soundness of 1−2−α, with 20 ≤ α ≤ 30, just by performing a match of a small string (4-5 characters). Due to its simplicity, verifying the election public data (vote encryptions and tally) in MP3 is 2.6 t...

As electronic structure methods are being used to obtain quantitatively accurate reaction energies and barrier heights for increasingly larger systems, the choice of an efficient basis set is becoming more critical. The optimum strategy for achieving basis set convergence can depend on the way that electron correlation is treated and can take advantage of flexibility in the order in which basis...

MP2, DFT and CCSD methods with 6-311++G** and aug-cc-pvdz basis sets have been used to probe the structural changes and relative energies of E-prop-2-ynylideneamine (I), Z-prop-2-ynylideneamine (II), prop-1,2-diene-1-imine (III) and vinyl cyanide (IV). The energy near-equivalence and provenance of preference of isomers and tautomers were investigated by NBO calculations using HF and B3LYP metho...