Quasiharmonic free energy and derivatives for many-body interactions: The embedded atom method

Autor:	GD Barrera, Neil L. Allan, E. P. Isoardi
Rok vydání:	2004
Předmět:	Vibration Lattice dynamics Physics Quantum mechanics Atom Empty lattice approximation Free energies Entropy of mixing Condensed Matter Physics Many body Electronic Optical and Magnetic Materials Lattice statics
Zdroj:	Physical Review B. 69
ISSN:	1550-235X 1098-0121
DOI:	10.1103/physrevb.69.024303
Popis:	We present a method using many-body potentials and lattice statics and quasiharmonic lattice dynamics for the calculation of the free energy of periodic crystals and its analytic derivatives with respect to all external and internal degrees of freedom. Derivatives are calculated by means of first-order perturbation theory and detailed expressions for the lattice sums required are presented. No approximations regarding the coupling of vibrations of different atoms are made. The approach is illustrated using the embedded atom method. As an example we calculate the temperature variation of the entropy and free energy of mixing of disordered RhPd by using configurational lattice dynamics, in which the free energies of a number of configurations is determined directly by means of fully dynamic structural minimizations. The method is particularly useful for quantities such as the vibrational contributions to the entropy of mixing.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::2f3ec49860c2b220b8022c6088152dc3 https://doi.org/10.1103/physrevb.69.024303 Zobrazit plný text záznamu