[Wien] The method of Madsen and Novak for calculating the U parameter is accurate for 5d metals ?

Pablo de la Mora Thu, 02 Jun 2011 07:13:28 -0500

Dear WIEN users,
     Compounds with 5d metals have magnetic properties, but due to the 
extended nature of the 5d orbitals the calculations give non-magnetic 
results, includding the Hubbard U (Uh).
I have calculated the Uh using the method proposed by G. Madsen and P. 
Novak:
         Notes about constraint LDA calculations to determine U 
<http://www.wien2k.at/reg_user/textbooks/Constraint_U.pdf>
which gives me a small Uh.
To stabilize the magnetic state I need to use an unphysically large Uh. 
Any suggestions?

Is this method suggested by Madsen and Novak accurate?
I have used in other compounds and it seems to give reasonable results, 
but these notes are not very clear (I could expand some issues in the 
notes to make them clearer).

[Wien] Magnetic properties or 5d metals

Peter Blaha Fri, 03 Jun 2011 15:06:48 +0200

If it gives a small U for a 5d system, it gives the expected result.

The method is reliable if   a)  most of the considered electrons (5d) are 
localized
within the atomic sphere and b) is only reliable when "LDA+U is appicable, that 
means
if "atomic physics" dominates and states are localized similar as in an atom.

Spin-orbit ??

[Wien] Magnetic properties or 5d metals

Pablo de la Mora Sat, 04 Jun 2011 07:18:53 -0500



Thank you, the Madsen and Novak method gives for Ir a value of Uh=0.7, 
but people use Uh=2.

For a metallic system the method seems to require a larger Uh, as you 
mention, the states are not localized.
Yes, SO is includded.

Reference: https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg04513.html