setting orbital occupancy matrix

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ajsmth · #1 Post by **ajsmth** » Thu May 03, 2012 4:21 pm

I'm investigating the UO2 system with VASP L(S)DA+U, which has been known to significantly improve the results compared to standard L(S)DA whilst creating many meta-stable states, and making it difficult to find the ground state. This is well documented in these papers :

http://link.aps.org/doi/10.1103/PhysRevB.79.235125
http://dx.doi.org.libproxy.ucl.ac.uk/10 ... 011.03.012

The approach that has been developed by these authors to avoid the meta-stable states is to explicitly set the occupation matrix of the f-orbitals (that can be viewed with LDAUPRINT>0) to a near GS configuration prior to the simulation. Does anyone have suggestions as to how this can be achieved in VASP?

It must be possible as the authors of these papers claim to have used VASP to perform their calculations.

I am aware that FERWE may allow for the diagonal of the occupation matrix to be set, but a further requirement to break the symmetry requires the off-diagonal elements be set as well.

I hope one of the VASP wizards is able to help....

Regards.

boris · #2 Post by **boris** » Wed Jul 18, 2012 3:24 pm

Hello

Sorry for answering this late!

We have indeed used vasp for controlling occupation matrices, but it requires some extra effort because it's not available in the original version. I suggest you contact me so that we can talk about it. My email address is: boris . dorado [at] cea . fr

Regards

Boris

kamalch · #3 Post by **kamalch** » Wed Jan 30, 2013 3:26 am

Hi
I have the same problem for setting occupancy for a YeAl3O12 system. Could you please let me know its solution. My email- writetokamal.1989@gmail.com