Quantifying local lattice distortions in alloys

Quantification of local lattice strain is essential for enhancing our understanding of structure-property relationships, particularly for high entropy alloys; but no common framework currently exists, with a number of possible quantifications in the literature. Here, local static and dynamic displacements are discussed, and different methods of describing their statistical dispersion presented. Similarly, the type of distribution measured, either offsite displacements or bond length, is considered alongside the different experimental and modelling techniques that can yield these distributions. This leads to a suggested numerical quantification for local lattice strain, to enable cross comparison between alloy systems using data obtained from different methodologies.