Correct and Accurate Polymorphic Energy Ordering of Transition-Metal Monoxides Obtained from Semilocal and Onsite-Hybrid Exchange-Correlation Approximations

The relative energetic stability of the structural phases common antiferromagnetic transition-metal oxides (MnO, FeO, CoO, and NiO) within semilocal hybrid density functionals are fraught with difficulties. In particular, MnO is known to be most difficult case for almost all approximations. Here, we show that meta-generalized gradient approximation (meta-GGA) constructed from cuspless hydrogen model Pauli kinetic energy (MGGAC) can lead correct phase as ground-state MnO. differences zinc blende (zb) rock salt (rs) structures computed using MGGAC found in nice agreement those obtained high-level correlation methods like random or quantum Monte Carlo techniques. Besides, have also applied onsite (closely related DFT+U) based on GGA meta-GGA functionals, it shown a relatively high amount Hartree–Fock exchange necessary obtain rs phase. Our present investigation suggests hybrids, both being computationally cheap, choice calculation having potential applications solid-state physics chemistry.