Re: [Wien] Hubbard U and mBJ
Hi, these are papers on mBJ+U: http://dx.doi.org/10.1063/1.4798706 http://dx.doi.org/10.1063/1.4828864 Very often, the procedure is to adjust U until the desired results are obtained. F. Tran On Fri, 1 May 2015, delamora wrote: Sorry for this question, it has been answered before; - (2/22/2012) So most likely mBJ + U gives the better solution, but probably the U should be smaller than in LDA+U, because mBJ already shifts the f-states a bit. but I am still confused, in GW and DMFT calculations the Hubbard U is still a parameter, so; Does the mBJ needs a not precisely known parameter? Saludos Pablo Dear P Blaha and F Tran, I would like to ask if with the modified Becke Johnson potential one should use the Hubbard U? Saludos Pablo ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
[Wien] Symmetry related
Dear Developers and Users Please what is wrong in having P1 symmetry? I got P1 when I initialized supercell calculations. In the mail archive P1 is regarded as less efficient. How can I improve the symmetry at the same time maintaining same structure? Could somebody elaborate please. With kind regards Lawal Mohammed___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] Symmetry related
On Sat, May 02, 2015 at 08:25:25AM +, Lawal Mohammed wrote: > Dear Developers and Users > Please what is wrong in having P1 symmetry? I got P1 when I > initialized supercell calculations. In the mail archive P1 is regarded > as less efficient. How can I improve the symmetry at the same time > maintaining same structure? Could somebody elaborate please. Lawal, 1) Nothing is wrong. P1 eans that there is no rotational symmetry available in your crystal. Rotattion, reflection, inversion, etc. 2) Unfortunately symmetry elements (other than traslation) are used by the codes to refuce the computationl cost so it may represent bad news. Traslation is also used, but that is implicit, as you are using solid state codes designed for crystals. 3) This computer experiment may help you to understand: Take a simple compund and reduce the symetry progressively. You will see how the computer time required for the calculation increases. The less symmetry operations available the higher the cpu involved. Bad news if your disponibility of computer resources is limited. Best regards, Dr. Víctor Luaña -- . ."Research is to see what everybody else has seen, and to / `' \ think what nobody else has thought"-- Albert Szent-Gyorgi /(o)(o)\ /`. \/ .'\ "Lo mediocre es peor que lo bueno, pero también es peor / '`'` \ que lo malo, porque la mediocridad no es un grado, es una | \'`'`/ | actitud" -- Jorge Wasenberg, 2015 | |'`'`| | (Mediocre is worse than good, but it is also worse than \/`'`'`'\/ bad, because mediocrity is not a grade, it is an attitude) ===(((==)))==+= ! Dr.Víctor Luaña, in silico chemist & prof. ! ! Departamento de Química Física y Analítica ! ! Universidad de Oviedo, 33006-Oviedo, Spain ! ! e-mail: vic...@fluor.quimica.uniovi.es ! ! phone: +34-985-103491 fax: +34-985-103125 ! ++ GroupPage : http://azufre.quimica.uniovi.es/ (being reworked) ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] Symmetry related
Dear Dr. Víctor Luaña, Thanks so much for the explanation. Kind regards Lawal Mohammed On Saturday, May 2, 2015 5:10 PM, Víctor Luaña Cabal wrote: On Sat, May 02, 2015 at 08:25:25AM +, Lawal Mohammed wrote: > Dear Developers and Users > Please what is wrong in having P1 symmetry? I got P1 when I > initialized supercell calculations. In the mail archive P1 is regarded > as less efficient. How can I improve the symmetry at the same time > maintaining same structure? Could somebody elaborate please. Lawal, 1) Nothing is wrong. P1 eans that there is no rotational symmetry available in your crystal. Rotattion, reflection, inversion, etc. 2) Unfortunately symmetry elements (other than traslation) are used by the codes to refuce the computationl cost so it may represent bad news. Traslation is also used, but that is implicit, as you are using solid state codes designed for crystals. 3) This computer experiment may help you to understand: Take a simple compund and reduce the symetry progressively. You will see how the computer time required for the calculation increases. The less symmetry operations available the higher the cpu involved. Bad news if your disponibility of computer resources is limited. Best regards, Dr. Víctor Luaña -- . . "Research is to see what everybody else has seen, and to / `' \ think what nobody else has thought"-- Albert Szent-Gyorgi /(o)(o)\ /`. \/ .'\ "Lo mediocre es peor que lo bueno, pero también es peor / '`'` \ que lo malo, porque la mediocridad no es un grado, es una | \'`'`/ | actitud" -- Jorge Wasenberg, 2015 | |'`'`| | (Mediocre is worse than good, but it is also worse than \/`'`'`'\/ bad, because mediocrity is not a grade, it is an attitude) ===(((==)))==+= ! Dr.Víctor Luaña, in silico chemist & prof. ! ! Departamento de Química Física y Analítica ! ! Universidad de Oviedo, 33006-Oviedo, Spain ! ! e-mail: vic...@fluor.quimica.uniovi.es ! ! phone: +34-985-103491 fax: +34-985-103125 ! ++ GroupPage : http://azufre.quimica.uniovi.es/ (being reworked) ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
Re: [Wien] Hubbard U and mBJ
Professor Tran, Thank you very much. Pablo de la Mora De: wien-boun...@zeus.theochem.tuwien.ac.at en nombre de t...@theochem.tuwien.ac.at Enviado: sábado, 2 de mayo de 2015 02:28 a. m. Para: A Mailing list for WIEN2k users Asunto: Re: [Wien] Hubbard U and mBJ Hi, these are papers on mBJ+U: http://dx.doi.org/10.1063/1.4798706 http://dx.doi.org/10.1063/1.4828864 Very often, the procedure is to adjust U until the desired results are obtained. F. Tran On Fri, 1 May 2015, delamora wrote: > > Sorry for this question, it has been answered before; > > - (2/22/2012) > > So most likely mBJ + U gives the better solution, but probably the U should > be smaller than in LDA+U, because mBJ already shifts the f-states a bit. > > > > but I am still confused, in GW and DMFT calculations the Hubbard U is still a > parameter, so; > > Does the mBJ needs a not precisely known parameter? > > Saludos > > Pablo > > > > > Dear P Blaha and F Tran, > > I would like to ask if with the > > modified Becke Johnson potential > > one should use the Hubbard U? > > > Saludos > > > Pablo > > > > ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
