The tungsten-182 Mössbauer spectra of a series of Keggin structure heteropolytungstates, [EW12O40]n- are reported. There is a very considerable variation in quadrupole coupling at the tungsten nucleus indicating considerable asymmetry in the electron distribution for the more electronegative elements E. The quadrupole coupling correlates well with the structural data, in particular with the dis...

A molecular conformation study on three 3-monosubstituted derivatives o f propene has been carried out by evaluating the EFG at the site o f the halogen nucleus using a semi-empirical LCAO-MO-SCF method. Calculations are performed on several conformers at INDO and CNDO level, using “sp” and “spd” valence basis sets, with Slater type orbitals as the basis functions. The results obtained for vari...

stabilizations and atomic level quadrupole coupling constant (cq) properties have been investigated for graphene–like monolayers (g–monolayers) of boron nitride (bn), boron phosphide (bp), aluminum nitride (aln), and aluminum phosphide (alp) structures. to this aim, density functional theory (dft) calculations have been performed to optimize the model structures and also to evaluate the cq para...

mp2 calculations with cc-pvtz basis set were used to analyze intermolecular interactions in f3cx···yli···nccn and f3cx···nccn···liy triads (x = cl, br; y = cn, nc) which are connected via halogen and lithium bonds. those complexes with the role of liy as halogen acceptor and lithium donor show cooperativity with energy values ranging between -1.97 and -2.92 kj mol-1. those complexes with simult...

density functional theory ,(dft) calculations have been performed to investigate the properties ofcarbon decorated (c-decorated) models of boron nitride (bn) nanocones. to this aim, the apex andtip of nanocone have been substituted by the carbon atoms to represent the c-decorated models. theresults indicated that dipole moments and energy gaps could reveal the effects of c-decorations onthe pro...

the electronic and structural properties of pristine and carbon doped (c-doped) boron nitride nano-ribbons(bnnrs) have been studied employing density functional theory (dft) calculations. total energies, gapenergies, dipole moments, and quadrupole coupling constants (qcc) have been calculated in the optimizedstructures of the investigated bnnrs. the results indicated that the stability and gap ...

Relativistic coupled cluster theory is used to determine accurate electric field gradients in order to provide a theoretical value for the nuclear quadrupole moment of (139)La. Here we used the diatomic lanthanum monohalides LaF, LaCl, LaBr, and LaI as accurate nuclear quadrupole coupling constants are available from rotational spectroscopy by Rubinoff et al. [J. Mol. Spectrosc. 218, 169 (2003)...

Non-perturbative time-dependent close-coupling calculations are carried out for the double photoionization of helium including both dipole and quadrupole radiation effects. At a photon energy of 800 eV, accessible at current synchrotron light sources, the quadrupole interaction contributes around 6% to the total integral double photoionization cross section. The pure quadrupole single energy di...