We have studied the vibrational properties of some of the compounds based on the Type II silicon, germanium, and tin-based clathrate materials using LDA electronic structure methods. The lattices in these framework materials have open cages which can contain weakly bound guest impurities, and these guests produce local (“rattling”) vibrational modes. Such modes may scatter the extended, heat ca...

The IR and Raman spectra of the title compound have been recorded and analyzed. The harmonic vibrational wavenumbers were calculated theoretically using Gaussian09 software package. Calculations were performed by HF and DFT levels using the standard 6-31G* basis sets. The data obtained from vibrational wavenumber calculations are used to assign vibrational bands found in the IR and Raman spectr...

Chirped-Pulse millimetre-Wave (CPmmW) rotational spectroscopy provides a new class of information about photolysis transition state(s). Measured intensities in rotational spectra determine species-isomer-vibrational populations, provided that the rotational populations can be thermalized. The formation and detection of S(0) vinylidene is discussed in the limits of low and high initial rotationa...

“What – if” analyses of the interfacial component of nanocrystalline materials (NCM), especially at higher temperatures, were performed using a two-dimensional model. What influence would thermal excitations have on the pair distribution function, the vibrational spectra and the specific heat, over the temperature range of 30–1200 K, if the NCM would be stable over this temperature range, i.e. ...

Anion photoelectron spectra taken at various photodetachment wavelengths have been obtained for GaX2 2 , Ga2X , Ga2X2 2 , and Ga2X3 2 ~X5P,As). The incorporation of a liquid nitrogen cooled channel in the ion source resulted in substantial vibrational cooling of the cluster anions, resulting in resolved vibrational progressions in the photoelectron spectra of all species except Ga2X2 2 . Electr...

We investigate the vibrational properties of ultrananocrystalline diamond (UNCD) using molecular dynamics simulations. We compare the vibrational spectra of two UNCD models of average grain size 2 and 4 nm with single crystal diamond and an isolated nanodiamond (ND) particle. The vibrational spectra of the ND particle and UNCD models exhibit the effect of phonon confinement as well as undercoor...