I need your collaboration, how can I calculate the values associated with Highest occupied energy level and lowest occupied energy level or if I can find them in the material project database
There isn’t a simple answer to this question.
In terms of crystalline materials, Materials Project has over 50k band structures calculated and these give you the energies of the valence band maximum and conduction band minimum, which are the highest occupied and lowest unoccupied states. But they do not give a reference point for these energies (e.g. compared to vacuum, or to other materials). Also, the simulation method we use (Density Functional Theory under the PBE approximation) systematically under-estimates the difference in energy between the highest-occupied and lowest-unoccupied states, so only relative trends are meaningful.
In terms of our molecules database, we share ionization energies and electron affinities, but this is the only information we share currently on the website.