Dear Halima As I wrote some days ago, 1,24 or 1.24 does not make any difference. Your structure is NOT wurtzite GaN at all... Check the right wurtzite structure, for example here (you may use "Vesta", or even "Avogadro" to open the .cif files).
http://www.crystallography.net/ lda_plus_u=.true. Hubbard_U(1)=8, Hubbard_U(3)=4.5, It may be a good choice, but you have got only two species, not three, and you do not need nspin=2. ecutwfc = 30.0, ecutrho = 120, As pointed out by Lorenzo, you should use ecutrho=8~10*ecutwfc HTH Giuseppe Quoting Lorenzo Paulatto <lorenzo.paulatto at impmc.upmc.fr>: > On 11/03/2013 07:18 PM, Halima Zaari wrote: >> dear quantum espresso users >> i tried to do input of GaN supercell with 56 atom >> I plots the dos of GaN it gives me mttalic behavior while in the >> literature is semiconductor. > > Dear Halima, > in your input you write: > ibrav=4,celldm(1)=12.06,celldm(3)=1,24,nat=56, ntyp=2, > > note that 1,24 is different from 1.24 : it will make your cell too small > which can cause a system to become metallic. > > I also noted that your value of ecutrho may be too low, as it is only > 4*ecutwfc and you are usng ultrasoft (note van=Vanderbilt) pseudopotentials. > > Finally, I do not understand what you're doing with the magnetization > and Hubbard U, but I'm don't know that method very well, hence I'll > leave any comment to more expert people. > > good work! > > > -- > Dr. Lorenzo Paulatto > IdR @ IMPMC -- CNRS & Universit? Paris 6 > phone:+33 (0)1 44275 084 / skype: paulatz > www: http://www-int.impmc.upmc.fr/~paulatto/ > mail: 23-24/4?16 Bo?te courrier 115, 4 place Jussieu 75252 Paris C?dex 5 > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum -- ******************************************************** - Article premier - Les hommes naissent et demeurent libres et ?gaux en droits. Les distinctions sociales ne peuvent ?tre fond?es que sur l'utilit? commune - Article 2 - Le but de toute association politique est la conservation des droits naturels et imprescriptibles de l'homme. Ces droits sont la libert?, la propri?t?, la s?ret? et la r?sistance ? l'oppression. ******************************************************** Giuseppe Mattioli CNR - ISTITUTO DI STRUTTURA DELLA MATERIA v. Salaria Km 29,300 - C.P. 10 I 00015 - Monterotondo Stazione (RM) Tel + 39 06 90672836 - Fax +39 06 90672316 E-mail: <giuseppe.mattioli at ism.cnr.it>
