Prediction of solution enthalpies of substitutional impurities in aluminium

A method for calculating the solution enthalpy of substitutional impurities in crystals is derived. A difficulty that arises in the ab initio calculation of the solution enthalpy is that the long-ranged elastic strain contribution cannot be computed within the rather small supercells that are computationally feasible. Here, we suggest combining atomistic ab initio methods with continuum elasticity theory to treat the problem of the long-ranged elastic strain. Additionally, it is shown that the solution enthalpy can be very useful for estimating the enthalpy of mixing.