Hello, I have got a band gap of 0.8 eV, with lattice constant 5.6533 Angstrom and the space group No. is 216, with two atoms in (0.0 0.0 0.0) and (0.25 0.25 0.25).
I have checked that: 1. In GaAs.inm_vresp, YES has been replaced by NO; 2. I have done the calculation as following steps: For the first scf run, I have set NR2V and indxc=5 in GaAs.in0; Change NR2V to R2V and run one more scf cycle; save lda; Set indxc=28 in GaAs.in0; cp GaAs.in0 GaAs.in0_grr and set index=50 in GaAs.in0_grr run_lapw -p -cc 0.00001 plot bandstructure Anything wrong with my procedure? yonghong On 2010?06?10? 05:06, F. Tran wrote: > Which value do you obtain? Did you use the correct structure? > In Table 1 of the following paper: > Tran et al., J. Phys.: Condens. Matter 19, 196208 (2007) > it is indicated which structure and lattice constant were used. > > In case.inm_vresp, you have to replace YES by NO for the normalization. > > > On Wed, 9 Jun 2010, yhzhao wrote: > > >> Hi, >> I have do all your suggested things, which given in the usersguide. However I >> cannot get the band gap, that is 1.64 eV for GaAs, as suggested by PRL 102, >> 226401 (2009). >> >> >> yonghong >> On 2010?06?09? 17:54, F. Tran wrote: >> >>> Hello, >>> >>> In order to use the modified Becke-Johnson exchange potential >>> you have to choose indxc=28 in case.in0 and indxc=50 in case.in0_grr. >>> >>> A few more things: >>> >>> In case.in0 you also need to replace NR2V by R2V such that the >>> exchange-correlation potential is written in case.r2v, which will >>> be used in the next iteration. >>> >>> You need case.inm_vresp such that case.vrespsum (which contains a >>> part of the kinetic-energy density) is created. >>> >>> There is no adjustable parameters. >>> >>> The LDA correlation potential is added to the MBJ exchange potential. >>> >>> The LDA exchange-correlation functional is used for the energy. >>> >>> The MBJ exchange potential is not the derivative of an energy functional, >>> which means that the method is not variational (i.e., the orbitals are >>> not the ones which minimize the total energy, which is LDA). >>> In particular, it means that you can not use forces to optimize internal >>> parameters. >>> >>> >>> On Wed, 9 Jun 2010, yhzhao wrote: >>> >>> >>> >>>> Dear Prof. Pblaha, >>>> >>>> I have tried to calculate something using the new exchange potential >>>> with indxc=50 as suggested by the usersguide. At first I want to repeat >>>> some data given by PRL 102, 226401 (2009), for example, the band gap of >>>> GaAs. I can get a band gap of 0.7 eV for GaAs, which is much better than >>>> 0.3 eV of lda, but not much better than the value given by you in PRL >>>> 102, 226401 (2009). In the calculation, I use the experimental lattice >>>> constant. The k-grid have been increased as dense as 20x20x20 and RKmax >>>> as large as 9.0. >>>> >>>> Is there any adjustable parameter for the MBJ calculation? Thanks. >>>> >>>> Regards, >>>> >>>> yonghong >>>> >>>> _______________________________________________ >>>> Wien mailing list >>>> Wien at zeus.theochem.tuwien.ac.at >>>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >>>> >>>> >>>> >>> _______________________________________________ >>> Wien mailing list >>> Wien at zeus.theochem.tuwien.ac.at >>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >>> >>> >> _______________________________________________ >> Wien mailing list >> Wien at zeus.theochem.tuwien.ac.at >> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >> >> >> >> >> _______________________________________________ >> Wien mailing list >> Wien at zeus.theochem.tuwien.ac.at >> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20100610/a3448730/attachment.htm>