The Kohn-Sham electronic density of states of liquid HCN: Tuning a long-range corrected exchange-correlation functional for predicting electron binding energies

Highlights: • The LC-wPBE was modified for reproducing ab initio electron binding energies. • The Kohn-Sham electronic density of states of liquid HCN is calculated. • The first ionisation energy of liquid HCN is estimated as 12.7 ± 0.5 eV. • The vertical electron affinity of liquid HCN is estimated as 1.08 ± 0.38 eV. -- Abstract: The electron binding energies and Kohn-Sham electronic density of states of liquid HCN were calculated by combining Born-Oppenheimer molecular dynamics with electron propagator theory and density functional theory. A modified long-range corrected Perdew-Burke-Ernzerhof exchange-correlation functional (LC-wPBE), where the parameter w was tuned for reproducing the electron binding energies of the HCN monomer and small aggregates was applied in the liquid state calculations. The average HOMO energy of HCN is red-shifted by $\sim 0.8$ eV relative to its gas-phase value. The vertical electron affinity of liquid HCN is estimated as $1.08\pm 0.38$ eV.