[Pw_forum] SOC

[Paolo Giannozzi]

On Monday 15 May 2006 21:54, Bhagawan Sahu wrote:

> for example, in pt.in
>
> 7
> 5D  3  2  4.00  0.00  2.10  2.40  1.50
> 5D  3  2  0.00 -0.20  2.10  2.40  1.50
> 5D  3  2  4.00  0.00  2.10  2.40  2.50
> 5D  3  2  0.00 -0.20  2.10  2.40  2.50
> 6P  2  1  0.00 -0.00  3.30  3.30  0.50
> 6P  2  1  0.00 -0.00  3.40  3.40  1.50
> 6S  1  0  2.00  0.00  2.60  2.60  0.50
>
> 6s is local so is placed at the end.
>
> four 5d states---> for j=3/2, there are 4 states so max occupation in
> these states is 4.0 (for up-spin) so down-spin occupation is zero.
> These counts for first two 5d orbitals (one for up and one for down,
> j=3/2).
> for j=5/2 there are 6 states, so maximum occupation in these states is 6.0
> but we have 4 remaining electrons so next two 5d states are for j=5/2
> (one up and one down j=5/2).

note that there are two 5d bound states (pseudized at the energy 
of the bound state), one for j=3/2 (4 electrons) and one for j=5/2 
(also 4 electrons); plus two unbound states, pseudized at the specified 
energy (-0.2 Ry), fifth column, as explained in the documentation:

 ener = energy (Ry) used to pseudize the corresponding state
             if 0.d0, use the one-electron energy of the all-electron state
             Do not use 0.d0 for unbound states!

> What I do not understand is the 6P states. for l=1 we have j=1/2 or 3/2
>
> for j=1/2, we have two states with maximum occupation 2.0
> for j=3/2, we have four states with maxmum occupation 4.0
>
> For Bi, there are 3 p-electrons  so
> the p config is
>
> 6P  2  1  2.00 -0.00  3.30  3.30  0.50
> 6P  2  1  0.00 -0.00  3.40  3.40  0.50
> 6P  2  1  1.00 -0.00  3.30  3.30  1.50
> 6P  2  1  0.00 -0.00  3.40  3.40  1.50
>
> Is this true?

if you remove the second and fourth lines, this is the ground 
state configuration. The unbound states may not be needed;
if needed, you have to specify an appropriate pseudization
energy, not 0.0 (see above)

> Also, since pseudotype =3 (ultrasoft), are the entries for rcut (meant 
> for norm conserving PP's) in Pt.in meaningful? I guess they are ignored 
> in the ultrasoft generation.

this code generate first a norm-conserving PP, and on top of that,
an ultrasoft PP, so rcut is definitely meaningful.

Paolo
-- 
Paolo Giannozzi             e-mail:  giannozz at nest.sns.it
Scuola Normale Superiore    Phone:   +39/050-509876, Fax:-563513 
Piazza dei Cavalieri 7      I-56126 Pisa, Italy