TLDR: Energy loss function, work function, and ionic liquids on exciting?

Hi all,
Please see this paper. My professor and I are trying to reproduce Figures 5 and 6, and we would also like to perform the same simulation on lithium. We eventually intend to perform these same simulations on ionic liquids (starting with BMIM-BF4), which is what my professor’s research focuses on. The software requires three files: one containing the density of states, one containing the energy loss function (or the dielectric function), and one containing the atomic number, unit cell volume in angstroms, Fermi energy, and work function. I have been working with both softwares for two-three months now and have struggled with what is mentioned in the title. Please direct me to any resources or instructions as to how to calculate the energy loss function and work function, as well as simulating ionic liquids on exciting.