Truncated Coulomb Potential

To simulate a real isolated 2D-layer convergence with vacuum size is required.

The use of a truncated Coulomb potential allows to achieve faster convergence in the vacuum size, eliminating the interaction between the repeated images. (see ref. Varsano) For a 2D system a box-like cutoff in the direction perperdicular to the sheet (in this case z) is applied. The used box size L_z = a_z (cell size in bohr) - 1 bohr = 32 bohr

Create the input file:

$ yambo -F 01_cut2D.in  -r

Open the input file 01_cutoff.in

Change the variables inside as:

RandQpts= 1000000          # [RIM] Number of random q-points in the BZ
RandGvec= 100        RL    # [RIM] Coulomb interaction RS components

CUTGeo= "box z"            # [CUT] Coulomb Cutoff geometry: box/cylinder/sphere X/Y/Z/XY..
% CUTBox
 0.00     | 0.00     | 32.0    |        # [CUT] [au] Box sides

Close the input file and run yambo

$ yambo -F 01_cut2D.in  -J 2D