Naslov
High-pressure Behavior of Solid F2 at low Temperatures

Autori
Etters, Richard. D. ; Kirin, Davor

Izvornik
Journal of physical chemistry (0022-3654) 90 (1986), 19; 4670-4673

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
solid F2 ; energy minimization ; C2/c structure ; vibron ; phonon

Sažetak
The equilibrium structures, orientations, and molar volume of solid F, at zero temperature are calculated at pressures between 0 and 100 kbar, by minimizing the Gibbs free energy of a general monoclinic lattice with two molecules per unit cell. This was accomplished with the Fletcher quasi-Newton method, which varies all the independent degrees of freedom until the force on each atom is eliminated. The resulting structures are C2/c, and no evidence of a phase transition is found, which is consistent with recent experimental data. On the basis of these calculated structures, the pressure dependence of the vibron stretch mode frequency is calculated by assuming that the crystal field of the solid acts as a small perturbation on the gas-phase intramolecular potential, and the k = 0 libron- and phonon-mode frequencies are determined with standard lattice dynamics techniques. These predicted frequencies are compared with results from recent Raman scattering measurements.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

POVEZANOST RADA