[Wien] the total energy from GGA+U calculations

2012-12-13 Thread Rolando Larico Mamani
Dear wien2k users,

Can we reliable in the total energy from GGA+U calculations to obtain  
the formation energies?

  With regards,


--
Rolando L. Mamani
Universidade de S?o Paulo
S?o Paulo-SP, Brasil.


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[Wien] LDA+U and Supercell: TETRA or ROOT in case.in2c?

2009-12-02 Thread Rolando Larico Mamani
Dear Prof. Blaha,

Thank you very much for your help.
I still have a doubt about it earlier.
Professor Blaha, when using LDA+U approximation, the results of the my
calculations for semiconductors materials are different if I use TETRA or ROOT.
Which one is correct?

Calculations with LDA+U approximation, the ORB using the density matrix of the
LAPWDM.
The subroutines that generate the density matrix are related directly to TETRA
in the LAPW2?
If they are related. How the they are related?

Thank you,

Rolando.

___
Rolando Larico Mamani
Departamento de F?sica dos Materiais e Mec?nica
Instituto de F?sica, Universidade de S?o Paulo
Cidade Universit?ria CEP 05508-090
Caixa Postal 66318
S?o Paulo, SP, Brasil
e-mail: rlarico at if.usp.br


Citando Peter Blaha pblaha at theochem.tuwien.ac.at:

 I have not used ROOT for several years!

 Use TETRA or TEMP. The choice between them is sometimes a matter of taste.

 Personally I prefer TETRA (since in principle it gives the correct
 occupation at T=0.
 However, it may require more k-points, 

 TEMP definitely helps scf-convergence (the larger the broadening,
 e.g.  0.020, the more it helps), but it may be dangerous since too
 large broadening leads to a wrong occupation and in magnetic systems
 the magnetic moment can be too small (or even vanish). Thus try to keep
 the broadening as small as possible (well below 0.010 ) and test it for
 your case and k-mesh.

 Rolando Larico Mamani schrieb:
  Dear Prof. Blaha and Wien-users,
 
  I use a supercell of 72 atoms to my calculations of semiconductors (GaN), in
  this case I use a few k's points (1 and 2) and in my case.in2c I use ROOT.
  So, to an LDA+U calculation (U in Ga) is necessary to change for TETRA in
  case.in2c?
  Best regards,


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[Wien] LDA+U and Supercell: TETRA or ROOT in case.in2c?

2009-12-01 Thread Rolando Larico Mamani
Dear Prof. Blaha and Wien-users,

I use a supercell of 72 atoms to my calculations of semiconductors (GaN), in
this case I use a few k's points (1 and 2) and in my case.in2c I use ROOT.

So, to an LDA+U calculation (U in Ga) is necessary to change for TETRA in
case.in2c?

Best regards,

-- 
Rolando Larico Mamani
Departamento de F?sica dos Materiais e Mec?nica
Instituto de F?sica, Universidade de S?o Paulo
Cidade Universit?ria CEP 05508-090
Caixa Postal 66318
S?o Paulo, SP, Brasil
e-mail: rlarico at if.usp.br






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