[Re:05] line 203 of file source/readin.f

Posted on : August 11, 2026 (Tue) 14:04:34

by Jerry Lee

Calculating the band gap of copper oxide (CuO) using Density Functional Theory (DFT) requires advanced methods like DFT+U or hybrid functionals (e.g., HSE06, mBJ). Standard LDA or GGA functionals severely underestimate or incorrectly predict CuO's insulating antiferromagnetic ground state due to strongly correlated Cu 3d electrons, often yielding a near-zero or incorrect metallic gap instead of the experimental ~1.2 to 2.2 eV.

CuO is a charge-transfer insulator. Standard local/semi-local approximations (LDA/GGA) fail to properly localize d-electrons on copper atoms. Standard PBE functionals typically yield an incorrect band gap or metallic behavior, misrepresenting the hybridization between Cu 3d and O 2p orbitals.