Analysis of the off-stoichiometry of Fe3N1+y with Density-Functional Theory in the Fe-N system

Density-functional theory has become one of the most prevalent methods
to determine the structure and stability of crystalline solids. To obtain
temperature-dependent free energies, however, which are essential in realworld
materials science, the excitation mechanisms have to be taken
Category 1 Application form (2016) 3
explicitly into account. The quasi-harmonic approximation (QHA), where
phonon spectra are calculated at different volumes to account for thermal
expansion or contraction, has become a very interesting approximation as
a trade-off between accuracy and computational resources. The aim for this
project is to assess the numerical precision of vacancy free energy
predictions for the Fe3N1+y nitride.