[Pw_forum] (no subject)

[Paolo Giannozzi]

On Sunday 03 August 2008 04:27, Padmaja Patnaik wrote:

> I have doubt in calculating magnetic moment.  Found few communications
> on this topic but no where a clear answer is found. If i want to find out
> the magnetic moment of an atom in a system, how am i going to get it.

a clear answer has been given many times on this forum: there is no
such thing as "the magnetic moment of an atom in a system". You can
define such a quantity by using appropriate projections onto atomic or
atomic-like wavefunctions or partition of the charge into domains, but
the results will depend upon the choice of the procedure

> Lowdin Charges:
>       Atom #   5: total charge =   4.5686, s, p, d, f =   0.2749   0.8321  
3.4616 
>       spin up       =   2.9945, s, p, d, f =   0.1449   0.4269  2.4227 
>       spin  down  =   1.5742, s, p, d, f =   0.1300   0.4052  1.0390
>       polarization =   1.4203, s, p, d, f =   0.0149   0.0217  1.3837
>
> How do i get the magnetic moment for the atom 5 from this? 

hint: polarization = spin up - spin down. Of course if you are looking
for orbital contributions as well things are much more complicated

Paolo
-- 
Paolo Giannozzi, Democritos and Udine University