Classical molecular dynamics simulation of UO2 to predict thermophysical properties

Molecular dynamics study on planar clustering of xenon in UO2

“…The cell volume dependence of UO 2 cohesive energy is shown in figure 1, where each unit cell contains 12 atoms (U m3m) and cotunnite (P nma) phases calculated by ab initio (VASP) compared with those predicted by interatomic potential models (shell model [7] and pair potential [8]). Note the latter curves have been shifted to have the same reference energy as ab initio results.…”

“…To model the collective behavior of xenon in UO 2 , the classical molecular dynamics method implemented in DL POLY 2 [32] code is employed, as well as the Basak's potential set for UO 2 [8]. When Xe atoms are involved, potentials listed in table 1 is added to the Basak's set where the parameters of (BM-fitted) rather than (BM) are adopted for Xe-U pairs.…”

“…The crystallographic, elastic and thermodynamic properties, static and high frequency dielectric constants, point defects formation energies, activation energies for lattice migration have been studied very well today and can be easily found in abundant literature [1,2,3,4,5,6]. A number of work on molecular dynamics (MD) simulations for UO 2 also has been published in recent years with classical interatomic potentials to get various thermodynamic and transport properties [7,8,9,10,11]. However, most of these studies focused on the stable fluorite phase, and bears a limitation that actual UO 2 might deviate from this structure locally due to irradiation damages.…”

Anisotropic thermal conductivity in uranium dioxide

“…Nevertheless the fact that the empirical potential still captures the anisotropic response of UO 2 in a temperature gradient (see inset of Fig. 1a), suggests that some of the physics arising from the phonon-spin scattering has been embedded into the force field description via the soft C 44 elastic constant and lattice anharmonicity 31 .…”

“…The inter-atomic forces between uranium and oxygen atoms were described by the short-range potential according to the study by Basak et al 31 , and the longrange electrostatic interactions were calculated by the Wolf summation method 33 . The length of simulation cells ranged from 16 to 60 nm for the simulations along the o1004 o1104 and o1114 crystallographic directions.…”