We present and discuss results of the calculations for BaTiO3 and SrTiO3 surface relaxation with different terminations using a semi-empirical shell model (SM) as well as ab initio methods based on Hartree-Fock (HF) and Density Functional Theory (DFT) formalisms. Using the SM, the positions of atoms in 16 near-surf ace layers placed atop a slab of rigid ions are optimized. This permits us deter...

Recent x-ray Compton scattering experiments in ice have provided useful information about the quantum nature of the interaction between H2O monomers. The hydrogen bond is characterized by a certain amount of charge transfer which could be determined in a Compton experiment. We use ab initio simulations to investigate the hydrogen bond in H2O structures by calculating the Compton profile and rel...

The Faddeev random phase approximation (FRPA) method is applied to calculate the ground state and ionization energies of simple atoms. First ionization energies agree with the experiment at the level of ∼10 mH or less. Calculations with similar accuracy are expected to provide information required for developing the proposed quasiparticle-DFT method.

For accurate calculations of the electronic structures of the heaviest elements and their compounds, where relativistic effects are of paramount importance, the usage of fully relativistic quantum chemical methods within 4component approximation is highly desirable. Such a usage encountered until recently difficulties for many electron systems with respect to the treatment of the electron corre...

Since 2000, atomic physicists have reduced the uncertainty of the helium-helium "ab initio" potential; for example, from approximately 0.6 % to 0.1 % at 4 bohr, and from 0.8 % to 0.1 % at 5.6 bohr. These results led us to: (1) construct a new inter-atomic potential ϕ 07, (2) recalculate values of the second virial coefficient, the viscosity, and the thermal conductivity of (4)He from 1 K to 10,...

In this work, theoretical investigations on carbon nanotube with oxygen atom have been carried out by firstprinciplescalculations and density functional theory and hartree fock theory in 3-216 and 6-316 basis sets. Theinteraction energy of the oxygen atom to a CNT is calculated. The effects of this substitutions have beeninvestigated on the during transplantation (10,0) single-walled carbon nan...

objective(s): recently we reported that the soybean 15-lipoxygenase (slo) inhibitory activity of pyrimido[4,5-b][l,4]benzothiazines largely depends on the orientation of sulfur atom of thiazine core towards feiii-oh in the active site pocket of the enzyme with subsequent oxidation of sulfur to sulfoxide. in this paper the results of a comparative study on the slo inhibitory activities of the me...

— An overview of the ab initio no-core shell model is presented. Recent results for light nuclei obtained with the chiral two-nucleon and three-nucleon interactions are highlighted. Cross section calculations of capture reactions important for astrophysics are discussed. The extension of the ab initio no-core shell model to the description of nuclear reactions by the resonating group method tec...