I have plotted the density of states (DOS) for my System with Hydrogen-rich and hydrogen lean . When the system is Hydrogen lean, the valence band maximum (HOMO) shifted towards Fermi level and bandgap of the system decreased.
How I can explain this DOS in terms of pi, pi*, sigma, sp3, sp2, localization, and delocalization of charge?
2 Answers
As noted by @Camps, you can gain a lot of information from a projected density of states by looking at the contribution of a given orbital. However, it won't directly tell you a lot of information about "bonding character," as you mention in your follow-up comment.
If you are specifically interested in "bonding character" when using a plane-wave DFT code, you're going to need to carry out a population analysis dedicated to such a task. Arguably, your best bet would be to carry out a Crystal Orbital Hamilton Population (COHP) analysis using LOBSTER. Another option that can provide similar orbital-based information is a periodic Natural Bonding Orbital (NBO) analysis, as implemented in this code. There is also the Solid State Adaptive Natural Density Partitioning (SSAdNDP) method, as implemented here.
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$\begingroup$ You got my point. I have LOBSTER data (ICOOP, ICOHP, Mullikan's Population analysis, etc) but I do not understand how to correlate there analysis with density of states. $\endgroup$– asthaFeb 3, 2021 at 8:30
In order to do that, you need to use the Partial Density of States (PDOS) were you can have the contribution of each atom/orbital to the DOS.
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1$\begingroup$ Yes, I have that. From DFT point of view, we can say about orbital contribution. But I need to understand in terms of bonding character. $\endgroup$– asthaFeb 3, 2021 at 2:38