Formation enthalpies for automated computational materials design*

The accurate calculation of formation enthalpies is crucial for computational materials design. For compounds chemically similar to their reference phases such as metal alloys, standard semi-local approximations to density functional theory (DFT) lead to accurate results [1]. When the phases are chemically dissimilar as in the case of oxides, DFT suffers from a lack of error cancellation leading to deviations of several hundred meV/atom compared to experimental values [2]. We use the automated computational materials design framework AFLOW [3] to benchmark correction schemes for ab initio formation enthalpies [2, 4]. These empirical methods can improve DFT predictions by a factor of 4 to 7. Zero-point vibrational and thermal contributions to the formation enthalpy are found to largely cancel each other.
[1] S. Curtarolo et al., Calphad 29, 163-211 (2005).
[2] V. Stevanović et al., Phys. Rev. B 85, 115104 (2012).
[3] S. Curtarolo et al., Comput. Mater. Sci. 58, 218 (2012).
[4] L. Wang et al., Phys. Rev. B 73, 195107 (2006).