Point defect modeling in materials: Couplingab initioand elasticity approaches

Abstract

Modeling point defects at an atomic scale requires to take special care of the long range atomic relaxations. This elastic field can strongly affect point defect properties calculated in atomistic simulations, because of the finite size of the system under study. This is an important restriction for ab initio methods which are limited to a few hundred atoms. We propose an original approach coupling ab initio calculations and linear elasticity theory to obtain the properties of the isolated point defect for reduced supercell sizes. The reliability and benefit of our approach are demonstrated for three problematic cases: the self-interstitial in zirconium, clusters of self-interstitials in iron, and the neutral vacancy in silicon.

Transport properties of C and O in UN fuels

“…Because our supercells are more than twice this distance in each direction, we think that the interaction between supercell replicas should have little effect on binding and migration energies. For isolated solutes and vacancy we used the ANETO code 38 to compute the elastic interaction energy between supercell replicas; it is less than 8%, 4% and 10% of the formation energy, respectively for C, O and N-vacancy, which is acceptable. The thickness of the UN(001) surface slab geometries was chosen following the work by Bocharov 15,16 , who showed that defect formation energies are converged for slabs thicker than five atomic layers.…”

The influence of alloying elements on the corrosion of Zr alloys

“…The defect formation energies (Emultiplied by the bulk modulus of the perfect t-ZrO 2 structure, with the aid of the ANETO software package [40].…”

Solute–Solute Interaction In α IRON: The Status QUO

“…In super cell calculations, point defects (here the solute atoms) are interacting with their images, and to evalu ate the effects of elastic strains the energies associated with those long-range elastic inter ac tions must be corrected. Application of a recently proposed method for this correction [34], which is expected to ameliorate the situation, is now under way.…”