[gpaw-users] How to calculate spin multiplicity of adsorbed O2 molecule on transition metal surface

[Thomas Olsen]

Hi Punit

I am not sure I understand what you are are trying to do. Since bulk Ni is metallic you cannot expect to get an integer half integer spin for the adsorbed molecule. Can you be a bit more precise on how you define the "S" you would like to calculate?

You should also be aware that the magnetic moment of the atoms you report are the integrals of the magnetization density inside the PAW spheres.  They are thus strongly dependent on the radius of the spheres and do not have a precise definite interpretation. The quantity that is meaningful is the total magnetic moment of a calculation.

/Thomas

Dear Users
Wish you a merry Christmas and happy new year. Currently I am trying to calculate spin multiplicity (2S+1 where S is the total spin) of an adsorbed O2 molecule on Ni surface having 2x2 surface atoms and 3 layers deep. I have done spin polarized calculation and got a magnetic moment of 0.72 per O-atom of O2 molecule i.e. a total magnetic moment of 1.44. I have given an initial magnetic moment of 2 to O2 molecule before adsorption and kept the fixmagmom=False in my GPAW calculator. Now please correct me if I am wrong that in order to calculate "S" I need unpaired electrons in adsorbed O2 molecule. Did the magnetic moment (i.e 1.44) of adsorbed O2 molecule can be treated as unpaired electrons for calculating spin multiplicity?
Any help will be appreciated.

With regards
Punit
IIT Bombay