Investigation of lattice dynamics for solid C60

Lattice dynamics of solid C60.

The lattice dynamics of C60 has been studied first by means of group theory and then by diagonalizing the dynamical matrix for two recently proposed intermolecular potentials. The libron and phonon energies are calculated as a function of momentum along various symmetry directions with and without phonon–libron interactions. The effects of these interactions on the density of states are also di...

High-pressure study of picosecond exciton dynamics in solid C60.

We have studied the singlet exciton decay by picosecond photoinduced absorption in films of C60, under pressures up to 62 kbar. The picosecond decay of excitons excited in the absorption tail continues to be dominated by broad distributions of lifetimes at high pressure. These results suggest that the distributions of lifetimes do not arise from variations in tunneling or hopping rates between ...

Lattice dynamics of solid N 2 with

Anharmonic lattice dynamics of solid potassium

An intcrionic potential proposed by Dagcns, Rasolt, and Taylor has been used in classical computcrsimulation experiments on solid K at 162.5 and 311 K. Results for the dynamical structure factor S{gre) are compared with lattice-dynamical calculations employing the self-consistent harmonic approximation plus cubic anharmonic corrections. The lattice&ynamical calculations are in good accord with ...

Orientational ordering of icosahedra in solid C60.

We determine the allowed structures for orientationally ordered icosahedral molecules on a fcc lattice such that there are four molecules per simple-cubic unit cell. The allowed space groups are Pm3, Pn3, and Pa3. In the latter two, an angle of rotation assumes a value not fixed by symmetry. The locations of all 240 atoms in the unit cell as deduced from the powder x-ray data of Heiney et al. a...