My goal is to produce a density of states for a 1d system.

It is my first time to use ypp; I am using yambo SVN revision 59.

First I wanted to check the interpolation of k-points.I have a 1d system with 64 k-points in the 1st Brillouin zone and I extrapolated to 128 points between k=0 and k=0.5 [2pi/a] using the following input for ypp

- Code: Select all
`bnds # [R] Bands`

electrons # [R] Electrons (and holes)

cooIn= "rlu" # Points coordinates (in) cc/rlu/iku/alat

% BKpts

0.00 | 0.00 | 0.00 | # Bands circuit

0.50 | 0.00 | 0.00 | # Bands circuit

%

BANDS_steps=128 # Number of divisions

% BANDS_range

20 | 31 | # Bands Range

%

% INTERPGrid

-1 |-1 |-1 | # Interpolation Grid

%

#GfnQPdb= "E < SAVE/ndb.QP" # [EXTQP G] Database

These are the results for the DFT part, where I have plotted the original energies as squares and the interpolated values as crosses:

While the conduction and valence band are represented more or less okay (still there is some wiggling), the interpolation gets confused for the other bands.

Note that in the unoccupied bands, the fit is confused even in regions far away from band crossings.

For the GW bands (not shown), the interpolation is even worse.

Are there any parameters I should adjust for the interpolation in the DFT and the GW? I tried to find some documentation on the INTERPGrid and GfnQP_* parameters, but I was not successful.

Best,

Leopold