Fermi Surfaces with Elk

The all-electron code Elk needs no help from c2x to generate a Fermi surface, so this example is only for completeness, and because c2x was used to do perform the co-ordinate translation from a Castep example.

Here Aluminium is considered, and the input file for Elk is

elk.in

tasks
  0
102

avec
  0.0000000   3.8162354   3.8162354
  3.8162354   0.0000000   3.8162354
  3.8162354   3.8162354   0.0000000

atoms
  1
  'Al.in'
  1
  0.0000000   0.0000000   0.0000000  0.0 0.0 0.0

ngridk
  9 9 9

vkloff
  0 0 0

plot3d
  0.0 0.0 0.0
  1.0 0.0 0.0
  0.0 1.0 0.0
  0.0 0.0 1.0
  55 55 55

The Al.in description of aluminium found in the species directory of the Elk distribution was used.

The above will use a 9x9x9 kpoint grid for the initial self-consistent calculation, task 0, which will take a few seconds, and then a 55x55x55 kpoint grid for the non self-consistent calculation with a frozen potential, task 102. This second stage takes a couple of minutes with so many points.

The output is visually identical to that given on the Castep page, save that energies are adjusted to set the Fermi level to zero.

Al Fermi surface