Vibrational excitations in systems with correlated disorder (2007)
Schirmacher, W., Schmid, B., Tomaras, C., Viliani, G., Baldi, G., Ruocco, G., ...
We investigate a $d$-dimensional model ($d$ = 2,3) for sound waves in a disordered environment, in which the local fluctuations of the elastic modulus are spatially correlated with a certain...
Vibrational properties of inclusion complexes: the case of indomethacin-cyclodextrin (2006)
Rossi, B., Verrocchio, P., Viliani, G., Scarduelli, G., Guella, G., Mancini, I.
Vibrational properties of inclusion complexes with cyclodextrins are studied by means of Raman spectroscopy and numerical simulation. In particular, Raman spectra of the non-steroidal,...
Fontana, A., Rossi, F., Viliani, G., Caponi, S., Fabiani, E.
We report new inelastic Raman and neutron scattering spectra for glasses with different degrees of fragility; the data are compared for each sample to obtain the Raman coupling function $C(\omega)$....
Benassi, P., Caponi, S., Eramo, R., Fontana, A., Giugni, A., Nardone, M., ...
We report Ultraviolet Brillouin light scattering experimental data on v-SiO2 in an unexplored frequency region, performed with a newly available spectrometer up to exchanged wavevector q values of...
Low-energy excess of vibrational states in v-SiO2: the role of transverse dynamics (2003)
Pilla, O., Fontana, A., Goncalves, J. R., Viliani, G., Angelani, L.
The study of the effects of the density variations on the vibrational dynamics in vitreous silica is presented. A detailed analysis of the dynamical structure factor, as well as of the current...
Transverse acoustic nature of the excess of vibrational states in vitreous silica (2002)
Pilla, O., Caponi, S., Fontana, A., Montagna, M., Rossi, F., Viliani, G., ...
We present a numerical simulation study of the density-dependence (rho = 2.2 - 4.0 g/cm^3) of the high-energy collective dynamics in vitreous silica at mesoscopic wavevectors (Q = 1 - 18 nm^-1). The...
Evidence of short time dynamical correlations in simple liquids (2002)
Scopigno, T., Ruocco, G., Sette, F., Viliani, G.
We report a molecular dynamics (MD) study of the collective dynamics of a simple monatomic liquid -interacting through a two body potential that mimics that of lithium- across the liquid-glass...
Temperature-dependent vibrational heterogeneities in harmonic glasses (2002)
Viliani, G., Duval, E., Angelani, L.
Numerical simulation is employed to study dynamical heterogeneities in model harmonic glasses whose atoms interact via three variants of the Lennard-Jones potential (monoatomic full Lennard-Jones,...
Frustration and sound attenuation in structural glasses (2000)
Angelani, L., Montagna, M., Ruocco, G., Viliani, G.
Three classes of harmonic disorder systems (Lennard-Jones like glasses, percolators above threshold, and spring disordered lattices) have been numerically investigated in order to clarify the effect...
Relaxation processes in harmonic glasses? (2000)
Ruocco, G., Sette, F., Di Leonardo, R., Monaco, G., Sampoli, M., Scopigno, T., ...
A relaxation process, with the associated phenomenology of sound attenuation and sound velocity dispersion, is found in a simulated harmonic Lennard-Jones glass. We propose to identify this process...
Fontana, A., Dell'Anna, R., Montagna, M., Rossi, F., Viliani, G., Ruocco, G., ...
New Raman and incoherent neutron scattering data at various temperatures and molecular dynamic simulations in amorphous silica, are compared to obtain the Raman coupling coefficient $C(\omega)$ and,...
Potential Energy Landscape and Long Time Dynamics in a Simple Model Glass (1999)
Angelani, L., Parisi, G., Ruocco, G., Viliani, G.
We analyze the properties of a Lennard-Jones system at the level of the potential energy landscape. After an exhaustive investigation of the topological features of the landscape of the systems,...
Montagna, M., Ruocco, G., Viliani, G., Di Leonardo, R., Dusi, R., Monaco, G., ...
We propose an explanation for the quadratic dependence on the momentum $Q$, of the broadening of the acoustic excitation peak recently found in the study of the dynamic structure factor of many real...
Potential energy topology and relaxation processes in a model glass (1998)
Demichelis, F., Viliani, G., Ruocco, G.
We use computer simulation to investigate the topology of the potential energy $V(\{{\bf R}\})$ and to search for doublewell potential's (DWP) in a model glass . By a sequence of Newtonian and...
Energy landscape, two-level systems and entropy barriers in Lennard-Jones clusters (1998)
Daldoss, G., Pilla, O., Viliani, G., Ruocco, G.
We develop an efficient numerical algorithm for the identification of a large number of saddle points of the potential energy function of Lennard- Jones clusters. Knowledge of the saddle points...
High frequency sound waves in vitreous silica (1998)
Dell'Anna, R., Ruocco, G., Sampoli, M., Viliani, G.
We report a molecular dynamics simulation study of the sound waves in vitreous silica in the mesoscopic exchanged momentum range. The calculated dynamical structure factors are in quantitative...
Search for tunnelling centres in Lennard-Jones clusters (1997)
Daldoss, G., Pilla, O., Viliani, G.
We report on numerical procedures for, and preliminary results on the search for, tunnelling centres in Lennard-Jones clusters, seen as simple model systems of glasses. Several of the double-well...
Low-frequency Raman scattering in model disordered solids: percolators above threshold (1997)
Pilla, O., Viliani, G., DellAnna, R., Ruocco, G.
The Raman coupling coefficients of site- and bond-percolators at concentration higher than percolation threshold are computed for two scattering mechanisms: Bond Polarizability (BPOL) and...
Raman scattering from fractals. Simulation on large structures by the method of moments (1995)
Viliani, G., Dell'Anna, R., Pilla, O., Montagna, M., Ruoco, G., Signorelli, G., ...
We have employed the method of spectral moments to study the density of vibrational states and the Raman coupling coefficient of large 2- and 3- dimensional percolators at threshold and at higher...
ORIGIN OF LIGHT SCATTERING FROM DISORDERED SYSTEMS (1995)
Benassi, P., Frizzera, W., Montagna, M., Viliani, G., Mazzacurati, V., Ruocco, G., ...
Anelastic light scattering is computed numerically for model disordered systems (linear chains and 2-dimensional site and bond percolators), with and without electrical disorder. A detailed analysis...
Absence of Definite Scaling Laws in Raman Scattering from Fractals (1992)
Benassi, P., Pilla, O., Viliani, G., Ruocco, G., Signorelli, G., Mazzacurati, V., ...
The frequency dependence of the Raman coupling coefficient $C(\omega)$ is calculated numerically for square and cubic percolation clusters. No general scaling law in terms of the macroscopic...
SPECTRAL ENERGY TRANSFER IN RUBY (1985)
Attar, A., Duval, E., Montagna, M., Monteil, A., Viliani, G.
The 1-phonon assisted non-radiative transfer in ruby is re-examined in the light of recent experimental results. It is shown that constructive (instead of destructive) interference among 1-phonon...
SPECTRAL ENERGY TRANSFER IN RUBY (1985)
Attar, A., Duval, E., Montagna, M., Monteil, A., Viliani, G.
The 1-phonon assisted non-radiative transfer in ruby is re-examined in the light of recent experimental results. It is shown that constructive (instead of destructive) interference among 1-phonon...
SPECTRAL ENERGY TRANSFER IN RUBY (1985)
Attar, A., Duval, E., Montagna, M., Monteil, A., Viliani, G.
The 1-phonon assisted non-radiative transfer in ruby is re-examined in the light of recent experimental results. It is shown that constructive (instead of destructive) interference among 1-phonon...
Splitting of the ruby fluorescence under stress (1984)
Monteil, A., Duval, E., Attar, A., Viliani, G., Lacroix, R.
A splitting of the R1 ruby fluorescence is observed when a pressure P is applied on the crystal along special directions. It is linear as a function of P2, in agreement with the theory. It comes from...
Splitting of the ruby fluorescence under stress (1984)
Monteil, A., Duval, E., Attar, A., Viliani, G., Lacroix, R.
A splitting of the R1 ruby fluorescence is observed when a pressure P is applied on the crystal along special directions. It is linear as a function of P2, in agreement with the theory. It comes from...
Splitting of the ruby fluorescence under stress (1984)
Monteil, A., Duval, E., Attar, A., Viliani, G., Lacroix, R.
A splitting of the R1 ruby fluorescence is observed when a pressure P is applied on the crystal along special directions. It is linear as a function of P2, in agreement with the theory. It comes from...