Thermodynamics of Molecular Chains with a Local Asymmetric Double-Well Potential

Abstract

The thermodynamics of one dimensional chains with asymmetric double-well on-site potential is investigated. Pseudo-Schrödinger equation resulting from the transfer integral method is solved numerically and in terms of semiclassical approximation. This allows exact calculation and qualitative interpretation of the partition function, free energy and the specific heat function. The specific heat exhibits a characteristic hump similar to the one observed in the structures with a symmetric double-well potential. In some systems, another extremely narrow and extremely high, peak might be developed indicating an entropy driven phase transformation. Comparison between this highly simplified model and more practical approaches to the phenomena of photoinduced phase transformations is discussed underlying the possibility of manifestation of quantum effects in some (spin-crossover) systems.