Utilizing Advanced Kinetic Energy Density Based Ingredients for Novel Local Hybrid Mixing Functions

Density functional theory (DFT) has become an invaluable tool across many domains of chemistry and materials science, a success made possible by the high accuracy and efficiency of modern density functional approximations (DFA). Despite continued progress in functional design, conventional DFAs suffer a poor description of the strong many-electron interaction (SMEI) and self-interaction error (SIE). Such deficiencies degrade accuracy in predictions of many properties important for energy applications, including band gaps, stretched bonds, catalysis, charge transfer processes, and reaction barriers¹.

Despite efforts to solve SIE and SMEI within DFT, there is no efficient functional applicable to both molecules and solids that solves the SIE and SMEI and maintains standard DFA accuracy at equilibrium². We investigate the local hybrid functional form, including a space dependent admixture of exact-exchange energy³, to address this absence. A recent local hybrid framework in the QUEST rapid development platform is used to develop local mixing functions from kinetic energy densities².

¹P. Mori-Sánchez, A. J. Cohen, and W. Yang, PRL 100, 146401 (2008)
²J. Sun, A. Ruzsinszky, and J. P. Perdew, PRL 115, 036402 (2015)
³Burke, K., Cruz, F. G., & Lam, K. C., JCP, 109(19), 8161–8167 (1998)