[Pw_forum] Calculations of magnetic systems by pwscf

[Stefano de Gironcoli]

The total magnetization is the integral of the magnetization in the cell

TM = \int (n_up-n_down) d^3r

The absolute magnetization is the integral of the absolute value of the magnetization in the cell

AM=  \int abs(n_up-n_down) d^3r

In a simple feromagnetic material they should be equal (except possibly for an overall sign)
In simple antiferromagnets (like FeO, NiO)  TM is zero and AM is twice the magnetization of
each of the two atoms.

For more complicated structure in order to define an atomic magnetization one should define,
somehow arbitrarily, integration volumes around the atoms and compute the integral in these
volumes. This is not implemented in the code but should be easy to write a tool for such purpouse.
Alternatively one can calculate atomic (and spin) projected density of states (using projwfc.x in PP)
and  extract a number from the integral of those PDOS up to the Fermi energy.

Stefano de Gironcoli


subhra at physics.rutgers.edu wrote:

> I would like to be clarified on a few things.
>
> In the older version of PWSCF there were two things in the output of a magnetic calculation: Total magnetization and absolute magnetization. What is the difference?
>
> I would also like to know how does one gets component projected magnetization. For example: If we have a system AB can PWSCF calculate the magnetization on A and B atoms separately?