Lattice vibrations in molecular crystals: polymorphism and phase transitions

Theory of Photoinduced Phase Transitions in Molecular Conductors: Interplay Between Correlated Electrons, Lattice Phonons and Molecular Vibrations

Dynamics of photoinduced phase transitions in molecular conductors are reviewed from the perspective of interplay between correlated electrons and phonons. (1) The charge-transfer complex TTF-CA shows a transition from a neutral paraelectric phase to an ionic ferroelectric phase. Lattice phonons promote this photoinduced transition by preparing short-range lattice dimerization as a precursor. M...

Vibrational Spectroscopy and Structural Phase Transitions in Molecular Crystals

Vibrational spectroscopy can give useful informa tian, both structural and dynamical, about phase transitions in molecular crystals. In particular, the data concerning the mechanism of the transformation at molecular level can be obtained. This is illustrated by examples of pure van der Waals crystals such as 3,5-dichloropyridine and 4-methylpyridine, hydrogen bonded malonic acid, inorganic fer...

Lattice- and molecular-dynamics studies of phase transitions in CsLiSO4.

We report results of a simulation of the phase transitions in CsLiSO4. These are based on our previously developed method for calculating parameter-free potential-energy surface for ionic molecular crystals. Our lattice-dynamical and molecular-dynamics studies show that the roomtemperature (Pnam) phase is unstable and transforms to the observed low-temperature (P1121/n) phase over approximately...

Phase transitions in liquid crystals

Phase Transitions in Lattice Qed

The main objective of the work presented here is to understand the appearance of phase transitions in pure gauge and scalar lattice QED, both in the compact as well as the noncompact formulations.