|
Electronic level alignment at a metal-molecule interface from a short-range hybrid functional
A. Biller, I. Tamblyn, J.B. Neaton, and L. Kronik Journal of Chemical Physics, 135, 164706 (2011) This study investigates whether the short-range hybrid functional HSE (Heyd-Scuseria-Ernzerhof) can accurately describe the electronic structure at metal-organic interfaces. Two prototypical systems are examined: benzene on graphite and benzene diamine on gold. While HSE performs better than semi-local density functionals, the results show it still falls short by approximately 1 eV compared to experimental photoemission data and GW approximation calculations. The quantitative discrepancies arise because HSE does not correctly capture the fundamental gap of the organic molecule or its renormalization by the metallic substrate, a limitation traced to missing long-range exchange and correlation components inherent to short-range hybrid functionals. The work demonstrates that long-range effects are essential for properly describing electronic level alignment at metal-molecule interfaces. |
