A neutron-scattering measurement was performed on pure amorphous Si. The radial distribution function derived from the wide momentum-transfer range spectra. These data are compared to theoretical models in 0--10-A\r{} real-space interval.

A neutron-diffraction measurement in the 0--23 A${\mathrm{\r{}}}^{\mathrm{\ensuremath{-}}1}$ inverse space interval was performed on pure amorphous Si. With structure factor obtained experimentally three-dimensional models were constructed by reverse Monte Carlo simulation for determination of atomic a-Si. The radial distribution function calculated directly from large-scale and derived traditionally these wide range spectra, as well.

We have modeled the photoinduced volume change in amorphous selenium. After photon absorption, we treated excited electron and hole independently within framework of tight-binding formalism. found covalent bond breaking networks with electrons, whereas holes contribute to formation interchain bonds. also observed a correlated samples. Our results provide new universal description, which can simultaneously explain expansion shrinkage. This model is supported by very recent situ surface height...

Hartree–Fock ab initio Raman spectra calculations and spectroscopic measurements were carried out on amorphous selenium in order to identify the characteristic vibrational mode due sigma bonds. Variations measured peak intensity observed as a consequence of band gap light illumination. Based our previous theoretical investigations we originate these variations from photoinduced covalent bond breaking.

The growth of amorphous carbon thin film on a [111] diamond surface has been studied by tight-binding molecular dynamics technique. Six different three-dimensional networks were constructed with periodic boundary conditions in two dimensions. Time-dependent nonequilibrium was simulated and densities, radial distribution functions, coordination numbers, bond angle distributions, ring statistics analyzed.

A quantum-chemical method has been developed to determine charge fluctuations in finite aperiodic clusters of amorphous silicon. Calculated atomic net charges are a close linear relationship bond-angle distortions involving first and second neighbors. Applying this continuous-random-network model 216 silicon atoms proposed by Wooten et al., we obtained 0.021 electron units for the rms deviation from neutrality.

The \ensuremath{\pi}-electron structure of amorphous carbon has been studied within the framework a tight-binding approximation. Graph theory is used to estimate density states near Fermi level.

Using the recently discovered time-dependent spin-orbit-photon interaction operator and first order perturbation theory, rate of spontaneous emission from triplet excitations is derived within two-level approximation for organic molecular solids conjugated polymers. The calculated rates corresponding radiative lifetimes agree very well with known experimental results. Present results are compared those obtained through traditional approach second theory in some crystals found to be better...

Insights into the structure of amorphous Si (a-Si) and hydrogenated (a-Si:H) have been made by analysing local configurations found in fragments large molecules. The source for this data is Cambridge Structural Database. Out almost 1800 analysed, a considerable number contain atoms triangular or planar square arrangements. It suggested that presence such a-Si could account first peak experimentally determined radial distribution function.

Abstract Conformational analysis of phenylbenzoate, a characteristic moiety several liquid crystal compounds, was done using the NDDO semiempirical molecular orbital method. Calculated and experimental torsional angles (the latter found in various model molecules) agree nicely. The most probable conformation DB-PBB (4-butylphenyl-4'-butylbenzoyloxy benzoate), existing solid phase probably also mesophase, is an extended one. C3-C4-C7-O8-torsional angle synclinal while C4-C7-O9-C10 periplanar....

Non-crystalline silicon networks were constructed by atomic deposition and rapid quenching. The tight-binding molecular dynamics (TBMD) method which had been developed for studying the growth of amorphous carbon structures (Kohary, K., Kugler, S. (2001) “Growth carbon: low-energy (MD) simulation bombardment,” Phys. Rev. B 63 193404), was applied. During relaxations temperature versus time functions display stretched exponential forms. most important structural properties analyzed. final...

We present the first molecular dynamics simulation of vacuum deposition amorphous selenium films. compare classical, tight-binding and Hubbard-term corrected methods. Densities, coordination defects, radial distribution functions, bond angles, dihedral intrachain interchain atomic correlations were investigated in obtained Local arrangements compared to results diffraction measurements.

Atomic scale computer simulations on structures and photoinduced volume changes of flatly obliquely deposited amorphous selenium (a-Se) films have been carried out in order to understand how the properties chalcogenide glasses are influenced by their preparation method. Obliquely a-Se thin contain more coordination defects larger voids than ones. To model electron excitation hole creation were treated independently within framework tight-binding formalism. Covalent interchain bond breakings...