Abstract
Constructed to satisfy 17 known exact constraints for a semilocal density functional, the strongly constrained and appropriately normed (SCAN) meta-generalized-gradient-approximation functional has shown early promise for accurately describing the electronic structure of molecules and solids. One open question is how well SCAN predicts the formation energy, a key quantity for describing the thermodynamic stability of solid-state compounds. To answer this question, we perform an extensive benchmark of SCAN by computing the formation energies for a diverse group of nearly 1000 crystalline compounds for which experimental values are known. Due to an enhanced exchange interaction in the covalent bonding regime, SCAN substantially decreases the formation energy errors for strongly bound compounds, by approximately 50% to 110 meV/atom, as compared to the generalized gradient approximation of Perdew, Burke, and Ernzerhof (PBE). However, for intermetallic compounds, SCAN performs moderately worse than PBE with an increase in formation energy error of approximately 20%, stemming from SCAN's distinct behavior in the weak bonding regime. The formation energy errors can be further reduced via elemental chemical potential fitting. We find that SCAN leads to significantly more accurate predicted crystal volumes, moderately enhanced magnetism, and mildly improved band gaps as compared to PBE. Overall, SCAN represents a significant improvement in accurately describing the thermodynamics of strongly bound compounds.
Original language | English (US) |
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Article number | 063801 |
Journal | Physical Review Materials |
Volume | 2 |
Issue number | 6 |
DOIs | |
State | Published - Jun 22 2018 |
Funding
We thank G. Kresse (University of Vienna) for useful discussions. We acknowledge support from the U. S. Department of Energy under Contract No. DE-SC0015106. Computational resources were provided by the Quest high performance computing facility at Northwestern University and the National Energy Research Scientific Computing Center (U. S. Department of Energy Contract No. DE-AC02-05CH11231).
ASJC Scopus subject areas
- General Materials Science
- Physics and Astronomy (miscellaneous)