QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: GJK on November 30, 2014, 19:01

Title: spin polarised zgnr -charge transfer
Post by: GJK on November 30, 2014, 19:01

Hi,

How to calculate charge transfer from Mulliken population in the case of spin polarised ZGNR ???

Do we have to add the spin up and spin down population densities on each atom and subtract from the atomic number???

Title: Re: spin polarised zgnr -charge transfer
Post by: Umberto Martinez on December 1, 2014, 15:32

If you wish to calculate charge transfer from Mulliken population, yes, sum spin up + spin down.

Title: Re: spin polarised zgnr -charge transfer
Post by: GJK on December 1, 2014, 16:39

Thank you

I calculated but the results are like this

1.Charge transfer value for spin polarised zgnr system=  -0.032 e
2.Charge transfer value for molecule adsorbed on spin polarised zgnr
      a. Molecule charge = 0.803 e
      b. zgnr charge       = -0.604 e
My question is the molecule and zgnr charges seem to be partial charges with charge transfer taking place from molecule to zgnr. But the partial charges are not equal. where does the remnant charge of about -0.2 e gone??? I did this analysis with Mulliken Population.
 For spin unpolarized calculation I got equal and opposite partial charges but why this discrepancy comes in spin unpolarized system
(or) 
the extra charge of -0.2 e has been utilized in the magnetic moment??? even then the total magnetic moment of the system is comming out to be -0.963(mu B)????

Your assistance is appreciable