# What does a density of states (DOS) plot show?

I have plotted the density of states using GGA-PBE exchange correlation functional for magnesium silcide but I really do not know what the equations involved are in this process, and how they relate to DFT?

• +1 But only one question per post please. For example if you ask what DOS means, then asking what a different thing means ought to be asked in a separate post. Also, can you cut out some of the whitespace in this picture so that it looks better? Mar 19 at 16:06
• @TristanMaxson thanks so much for doing that!! Mar 19 at 18:12
• You may take a look at this post: mattermodeling.stackexchange.com/questions/1791/…
– Jack
Mar 20 at 7:13

In solid state physics and condensed matter physics, the density of states (DOS) of a system describes the proportion of states that are to be occupied by the system at each energy. The density of states is defined as $$D(E) = N(E)/V$$, where $$N(E)\delta E$$ is the number of states in the system of volume $$V$$ whose energies lie in the range from $$E$$ and $$E + \delta E$$.