I recently came across works that display the highest occupied crystalline orbital (HOCO). I am trying to compare some results I find in VASP to previous molecular calculations done with atom-centered basis sets, and it would be nice to be able to compare the HOCO to the molecular HOMO orbital. For those familiar with VASPKIT, it is possible to produce real space wave function isosurfaces from the VASP WAVECAR file (

*command 511*), where the HOCO is at the Valence Band Maximum (VBM).1 I understand that this is not a VASPKIT forum, but I was hoping someone could explain to me whether it is fair to compare these constructions to atom-centered molecular orbitals, or whether I should not consider this as an orbital at all. Finally, what would the units of this isosurface be? The VASPKIT paper, nor any paper I have found with such figures, present numerical isosurface values...

[1] Section 3.7, eqn. 29 -- https://www.sciencedirect.com/science/a ... 5521001454

Thanks,

Ryan