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.

Hi Angela,

To give you a vague answer that will at least point you in the correct direction, the EELS is one of many things computed and output from `src/dielmat.f90`

. So to run this output, add the property dielmat to exciting’s input: The file you want is of the form `LOSS_*.OUT`

Skimming the source code, it’s clear you need to compute the momentum matrix elements first. The code will attempt to read this plus eigenvalues and occupations. As such, you *may* need to run a ground state calculation that computes the momentum matrix first, then change the input to compute the`dielmat`

… or it may be doable as a single calculation (put both momentum matrix and dielmat property fields in the input)

As I’ve never run EELS with exciting, I can’t be more specific. I note that ELLS is briefly mentioned as eq. 99 in DOI:10.1088/0953-8984/26/36/363202

PS, if your cell contains > 100 atoms, these calculations are likely to be computationally expensive.

Cheers,

Alex