Tetrahydrobenzo[b]pyran derivatives 1 were utilized for the synthesis of several new pyrano[2,3-d]pyrimidine derivatives 2. Compound 2 was obtained in the presence of Ac2O/H2SO4 (as a catalyst) and was confirmed by spectroscopic data such as IR, 1H NMR and 13C NMR. Ab initio calculation was carried out to study geometric optimization, t...

The ab initio calculation of the ballistic current using full electronic structure and phonon dispersion shows that much larger responses can exist away from band-edge, provides a qualitatively different understanding for real materials.

SUPSIM is a web application, based on the Java Servlet technologies, to compute ab-initio potential energy surfaces of molecular systems for subsequent dynamical properties calculation. We describe the architecture of SUPSIM, its current implementation, and its possible future developments to tackle chemical systems of increasing complexity.

An algorithm for calculating the scattering factors of atomic fragments in molecules as defined by the Stockholder recipe is presented. This method allows the calculation, from ab initio molecular wave functions, of structure factors including individual anisotropic atomic temperature factors. These structure factors agree with the model used in most leastsquares multipole-refinement procedures...

The results of ab initio calculation of E1 amplitudes, lifetimes, and polarizabilities for several low-lying levels of ytterbium are reported. The effective Hamiltonian for the valence electrons Heff has been constructed in the frame of CI+MBPT method and solutions of many electron equation HeffΦn = EnΦn are found. PACS. 31.15.Ar, 32.10.Dk, 32.10.Fn Typeset using REVTEX

We present an ab initio method of calculation of isotope shift in atoms with a few valence electrons, based on the configuration-interaction calculation of energy. The main motivation for developing the method comes from the need to analyze whether differences in isotope abundance in early universe can contribute to the observed anomalies in quasar absorption spectra. The current best explanati...

The leading order low energy parameters like the pion decay constant or the quark condensate are well-known from “classical” low energy theorems and experiments. It is a challenge, however, to find these parameters based exclusively on an ab-initio QCD calculation. We discuss results of a quenched lattice calculation of low energy constants using the chirally improved Dirac operator. Several la...

This paper describes a hybrid ab initio quantum mechanical/molecular mechanics (QM/MM) method for calculating activation free energies of chemical reactions in solution, using molecular mechanics force fields for the solvent and an ab initio technique that incorporates the potential from the solvent in its Hamiltonian for the solute. The empirical valence bond (EVB) method is used as a referenc...