Eigenvalues and density of states

[Niles]

Hi guys

I have an analytical expression f(x) for my density of states, and I have plottet this. Now, I also have a complete list of my Hamiltonians eigenvalues.

When I make a histogram of these eigenvalues, I thought that I should get an exact (non-continuous) copy of my plot of f(x). They have the same form, but they are not to scale, i.e. f(x) has a maximum at ~100, while the histogram has a maximum at ~60.

Is there an error somewhere, or am I wrong to expect that they should be "exact" copies?

 

[Rajini]

I am not sure whether i am correct!
some scale factor for eigenvaues or for DOS?
Also check with units of y-axis (i often get these errors when i convert meV to cm^-1)
or your data is convoluted already?

 

[Niles]

The units are the same (I have checked).

So you believe they should be the same?

 

[Manchot]

The units of a numerical histogram depend on the bin size chosen. Are you remembering to divide by the width of the bin?

 

[Niles]

The units of a numerical histogram depend on the bin size chosen. Are you remembering to divide by the width of the bin?

Isn't a histogram unit-less?

 

[Manchot]

Yes, a histogram is unitless. That's why you need to divide by the bin size to get it in units of 1/energy (or 1/energy/volume, if that's what you're dealing with).

 

[Niles]

I see. Thanks - I'll play around with it to see if it works. Thanks.