GW convergnce order

Concerns issues with computing quasiparticle corrections to the DFT eigenvalues - i.e., the self-energy within the GW approximation (-g n), or considering the Hartree-Fock exchange only (-x)

Moderators: Davide Sangalli, andrea.ferretti, myrta gruning, andrea marini, Daniele Varsano

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kazemoor
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Joined: Tue Jun 22, 2010 6:27 am

GW convergnce order

Post by kazemoor » Fri Aug 13, 2010 9:29 am

Dear All
To gain correct GW qp , There is not comprehensive test convergence in the forum. Could any link available that discuss all nedeed parameters and thier orders that should be converged step by step?
Best regards
Ali Kazempour,Isfahan Univ. Of .Tech, Iran

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myrta gruning
Posts: 240
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Re: GW convergnce order

Post by myrta gruning » Fri Aug 13, 2010 10:30 am

Dear Ali

a discussion on convergence with parameters of qp within the GWA can be found in the review "Quasiparticle Calculations in Solids " in Solid State Physics
Volume 54, 1999, Pages 1-218 by Aulbur et al., doi:10.1016/S0081-1947(08)60248-9. If you do not have access to the journal there is a link to a preprint in our free lectures page. There you can find other useful references.

To find a relation between the theory and the variables in yambo you may give a look to our online documentation. In fact a qp calculation in yambo consists of 3 runlevels:
1-Calculation of exchange part of the self energy
2-Calculation of the screening (W) within the plasmon pole (usually)
3-Calculation of the correlation part of the self energy
Note however that some of the variables changed name in the present version of yambo (while they appeared with their old one in the documentation).

I hope this helps. My advice is to start "playing" with e.g. Si, that is also the example used by Aulbur.

Best,
m
Dr Myrta Grüning
School of Mathematics and Physics
Queen's University Belfast - Northern Ireland

http://www.researcherid.com/rid/B-1515-2009

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