We apply the relativistic configuration-interaction valence-bond method to calculate various characteristics of the alkali-metal RbCs dimer. These include the electronic potentials and transition dipole moments between the ground and first excited states and permanent dipole moments of the X 1sigma+ and a 3sigma+ states of the ground configuration. In addition, we estimate the lifetime of the r...

Excitation of HeNe by synchrotron light just below the frequency of the 1s → 3p transition of isolated He has been recently shown to be followed by resonant interatomic Coulombic decay (ICD). The vibrationally resolved widths of the ICD states were extracted with high precision from the photoion spectra. In this paper, we report the results of ab initio calculations of these widths. We show tha...

In this work, we have calculated ab initio the vibrational modes and the phonon frequencies for the SiC (100) surfaces. Our results are in good agreement with the available experimental data whenever this comparison is possible: in fact, most of our obtained results are predictions. For the accepted models of the C-terminated surfaces in the c(2!2) reconstruction, while in the bridge-dimer mode...

We explore the use of ab initio, density-functional methods for the study of large-scale materials problems. Three examples are presented: (i) the interplay of surface and edge reconstructions in long silicon nanowires, where we examine the effects on electrical and mechanical properties; (ii) the calculation of solvation effects based on ab initio dielectric models, where we derive the dielect...

The density functional based calculations of the electronic structure of YMnO3 are performed for selected spin configurations and from the differences of the total energies the exchange integrals are determined. To improve the description of strongly correlated 3d electrons of Mn the LDA + U method is employed. The strongest exchange interaction is found between the nearest neighbor Mn spins, t...

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...

Enzymes which hydrolyse ATP cause an exchange of 180 of labelled Pi in the presence of ADP. A theory for the evaluation of rate constants from an observation of the time dependence of the concentration of the various Pi species is presented. Application to the 180 exchange catalysed by myosin SI as observed by 31P-NMR shows excellent agreement with values o f the rate constants determined earlier.

The relativistic configuration interaction valence-bond method has been used to calculate permanent and transition electric dipole moments of the KRb heteronuclear molecule as a function of internuclear separation. The permanent dipole moment of the ground-state X S potential is found to be 0.30~2! ea0 at the equilibrium internuclear separation with excess negative charge on the potassium atom....

The existence and stability of atoms rely on the fact that neutrons are more massive than protons. The measured mass difference is only 0.14% of the average of the two masses. A slightly smaller or larger value would have led to a dramatically different universe. Here, we show that this difference results from the competition between electromagnetic and mass isospin breaking effects. We perform...