[DFTB-Plus-User] final magnetic moment for each atom in the system

Benjamin Hourahine benjamin.hourahine at strath.ac.uk
Fri Mar 15 09:22:35 CET 2013

Hello Robyn,

you need to make a Mulliken analysis, and then look at the spin up and spin down resolved
values from detailed.out. For colinear spins, this is just the difference in the net up and down 
channel charges. In order to investigate different spin pattern, you will need to break spin
symmetries by setting the initial spin directions (see the manual for an example). 

In anti-feromagnetic ordering the net spin is zero, but unless you initially set some spins to 
be up and others to be down, the code will probably find a non magnetic state instead.
To realistically investigate the question of paramagnetism vs. feromagnetism etc. the first
step is probably to calculate effective Heisenberg model parameters by looking at energy
changes between different spin patterns. I'd suggest you look at some of the theoretical
literature on dilute magnetic semiconductors for a discussion of what is involved here,
papers by Satao and Katayama-Yoshida for example.



      Dr. B. Hourahine, SUPA, Department of Physics,
    University of Strathclyde, John Anderson Building,
            107 Rottenrow, Glasgow G4 0NG, UK.
    +44 141 548 2325, benjamin.hourahine at strath.ac.uk

  Strathclyde 2012 THE Awards UK University of the Year

   The University of Strathclyde is a charitable body,
        registered in Scotland, number SC015263
From: dftb-plus-user-bounces at dftb-plus.info [dftb-plus-user-bounces at dftb-plus.info] On Behalf Of Robyn.Shi at csiro.au [Robyn.Shi at csiro.au]
Sent: 15 March 2013 02:24
To: dftb-plus-user at dftb-plus.info
Subject: [DFTB-Plus-User] final magnetic moment for each atom in the system

Dear DFTB,

We did collinear spin polarization for our system and have got converged results. Might we ask you help to introduce how we can look at the final magnetic moment for each atom in the system, and furthremore to determine the magnetic properties, such as ferro, anti-ferro, or para?

Many thanks.

Best regards,


From: dftb-plus-user-bounces at dftb-plus.info [dftb-plus-user-bounces at dftb-plus.info] On Behalf Of Bálint Aradi [balint.aradi at bccms.uni-bremen.de]
Sent: Sunday, 10 March 2013 10:42 PM
To: User list for DFTB+ related questions
Subject: Re: [DFTB-Plus-User] What is SCC error?

Dear Chao,

> What is SCC error? In the manual, it says that SCC error is the error in
> the charges, How to get the charges?

This is the error in the Mulliken charges: maximal difference between
the charges used to build the Hamiltonian and those obtained after the
diagonalization of the Hamiltonian. The latter you can see in
detailed.out. The charges used to build up the Hamiltonian are not given
out, they are created by mixing various previous charges.

Best regards,


Dr. Bálint Aradi
Bremen Center for Computational Materials Science, University of Bremen
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