[QE-users] Help in spin polarized calculation for surface dangling bonds

[Lorenzo Sponza]

Dear Quantum ESPRESSO users and developpers,

I need some help to set up a calculation of a Si(111) 1x1 surface. This 
surface is characterized by dangling bonds that spoil the electronic 
states around Fermi. In literature, two approaches are usually adopted. 
One consists in saturating the surface with H atoms, the other consists 
in performing a spin polarized calculation.
I want to give both methods a try, but I stuck when it comes to set up 
the spin polarized input file. I set nspin=2, but I'm perplexed about 
the value to give to starting_magnetization since I have only Si atoms 
here, and in this specific case it is not clear to me how this variable 
is interpreted and used by the code.
Finally, is there any attention to be paid in choosing the 
pseudopotential or in specifying the input_DFT variable? I've used PBE 
scalar relativistic PAW pseudos so far.

Many thanks for your help.

-- 
Dr. Lorenzo Sponza

Chargé de Recherche au CNRS
Université Paris-Saclay, ONERA, CNRS Laboratoire d'étude des 
microstructures (LEM)
29 Avenue de la division Leclerc, 92322 Châtillon
Tel: +33146734464

ETSF Research Team Leader
European Theoretical Spectroscopy Facility
17 Sart-Tilman B-4000 Liège, Belgium