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Ab Initio Studies Of The Phase Transitions In K2Seo4, H. M. Lu, John R. Hardy
Ab Initio Studies Of The Phase Transitions In K2Seo4, H. M. Lu, John R. Hardy
John R. Hardy Papers
An ab initio model is developed for the potentials in ionic molecular solids in which the electron covalency within the molecular ions substantially affects the interionic interactions. By treating the intermolecular and intramolecular interactions on the basis of the true electron charge densities of the molecular ions, this new model leads to an accurate parameter-free description of the potentialenergy surfaces for such crystals. We performed first-principles static structural relaxation, supercell molecular-dynamics simulation, and lattice-dynamics studies for the room-temperature paraelectric phase and the lower-temperature ferroelectric superstructure of K2SeO4 and predicted with good accuracy the transition from the former …
First-Principles Simulations Of Ionic Molecular Solids: The Phase Transitions In K2Seo4, H. M. Lu, John R. Hardy
First-Principles Simulations Of Ionic Molecular Solids: The Phase Transitions In K2Seo4, H. M. Lu, John R. Hardy
John R. Hardy Papers
We present a new approach to first-principles simulations of the statics and dynamics of ionic molecular crystals. It is shown that the new method gives very realistic simulations of the phase transitions in K2SeO4 and that a double-well type of structure in the potential-energy surface is the driving mechanism of these phase transitions.