Hi Francesco,
have you tried to plot the bands? Do they behave OK?
You use 4x4x4 mesh with 0 shift, which is wrong, basically you reduce
the valuable amount of points in this way (should be 0.5 shift for even
number of points).
Anyhow, this won;t matter, if you plot the bands.
Here are my GGA pseudos with which I obtain 0.65eV in wurtzite.
pe Cadmium with 4d in valence
tm2 2.1
Cd pbr
0.0 0.0 0.0 0.0 0.0 0.0
8 4
5 0 2.00 0.00
5 1 0.00 0.00
4 2 10.00 0.00
4 3 0.00 0.00
2.43 2.55 1.50 3.00 1.10 0.70
#23456789012345678901234567890123456789012345678901234567890
pe Selenium
tm2 2.0
Se pbr
0.0 0.0 0.0 0.0 0.0 0.0
6 4
4 0 2.00 0.00
4 1 4.00 0.00
4 2 0.00 0.00
4 3 0.00 0.00
1.90 2.00 2.90 2.90 1.10 1.10
#2345678901234567890123456789012345678901234567890
Alex.