
Speciale, 3. modul, 2013, id:285  
Vejleder:  Jeppe C. Dyre 
Findes på RUb:  Ja 
English abstract
It has been shown [1] that for liquids exhibiting strong correlation between its NVT virial and potential energy equilibrium fluctuations, one can, to a good approximation, define isomorphic curves in the densitytemperature phase diagram, along which structure, dynamics, excess entropy, heat capacity etc. are all invariant. We investigate this behavior via MDsimulations in the FCCcrystalline state for LennardJones systems and show that the strong correlation here is even more pronounced than for the liquid. This implies that isomorphic curves exist in the crystal phase, as well. We confirm this by studying the following predicted invariance: (1) The structure via the radial distribution function and structure factor, (2) shortranged dynamics via the velocity autocorrelation function, (3) longranged dynamics via meansquare displacement of crystal vacancies, (4) aging via the relaxations of the system after instantaneous jumps between isomorphic state points. In all cases we compare the results with similar results along isochors and isotherms. In addition we investigate sodiumchloride in the crystal phase modeled by a potential consisting of a LennardJones and a Coulomb term in a FCC structure. This system exhibits correlations just below the limit of strong correlations, and as a consequence has less welldefined isomorphs.