Density of States Plugin

Density of States Plugin

The density of states plugin calculates the total density of states for each spin in any number of UR XML documents subject to comparison. Eigenvalues data are taken from the spectrum elements in UR XML documents. Users should set the fermi energy level, eigenvalue energy bounds, the broadening coefficient η, and the convolution function (Gaussian or Lorentzian).

Example: Fe Siesta

The density of states for a calculation on Iron can be computed by Siesta very simply using their eig2dos.f post-processing program. A short tutorial on how to compute the total density of states (TDOS) using Siesta can be found here.

A snippet of the first few lines of the Fe.EIG input file from Siesta reads

       -5.8930 0.1 1000 -10 20
    15     2  1099
    1   -10.80611    -9.24394    -7.00395    -6.86797    -5.65105    -5.52881     1.72815    18.88233    22.38273    22.86284
         31.42345    46.20575    50.45780    67.32764    84.65541    -9.39987    -7.26666    -5.23865    -4.20409    -3.82891
         -3.13974     3.14411    19.44661    22.86224    23.75613    32.56247    47.34424    51.55807    68.28392    86.46501
    2   -10.70644    -9.18151    -7.36545    -6.98549    -6.46030    -4.99808     3.00934    16.22948    20.00383    28.12197
         33.65286    45.55081    50.13577    64.44039    80.20697    -9.41608    -7.20465    -5.95030    -4.24959    -3.76579
         -2.94110     4.22954    16.86089    20.63950    28.88385    34.78921    46.67856    51.19879    65.42094    81.85403
    3   -10.41362    -9.10936    -8.24220    -7.08832    -6.66494    -4.60495     5.08675    11.99033    19.31753    32.75891

From this we can read that the fermi energy is -5.893 eV, the minimum eigenvalue energy is -10.0 eV and the maximum is 20 eV, and the broadening coefficient is η = -0.1. The plot from Siesta is shown below

If we run the density_of_states plugin with the same parameters and the UR XML translation of the Siesta Fe simulation, the HTML output is

The two curves shown are one for each spin that is not treated separately in the Siesta plot.