[Pw_forum] Tb09-MetaGGA convergence problem

[plgong]

Dear Éric Germaneau, 
     I did a test on gap of Silicon using tb09. This time I used a another pseudopotential (Si.tpss-mt.UPF)
and it converged lastly. But the gap converged to 1.75 eV, larrger than experimental results （1.17eV）.
I saw a literature on the gap calculaion with MBJ (tb09) for silicon, and it showed that theoretical results coincide with that in experiment. I an confused. 
     A few days ago, I tried to installed the libxc linked to QE, and my procedure was the following, 
     1. intall libxc;
     2. install QE and modify make.sys, 
(DFLAGS = -D__LIBXC -D__INTEL -D__FFTW -D__MPI -D__PARA -D__SCALAPACK $(MANUAL_DFLAGS
LD_LIBS = -L/home/plgong/software/QE512/libxc-2.2.2/lib   -lxcf90 -lxc)
    The above make QE linkig libxc sucessfully.
But, I have a question: I do not understand the tips 
1. move to libxc, getting rid of all duplicated functionals, keeping only
   those that are not available in libxc;
2. add the possibility to use any functional from libxc (currently only a few
   can be used). This may require serious restructuring work in our XC
   functional (il-)logic, that has become clumsy, obscure and redundant.

Whether the above installation leads to larger gap in my test?


Best wishes
P L Gong



> -----原始邮件-----
> 发件人:"Éric Germaneau" <germaneau at sjtu.edu.cn>
> 发送时间:2015年4月8日 星期三
> 收件人:"PWSCF Forum" <pw_forum at pwscf.org>
> 抄送:
> 主题:Re: [Pw_forum] Tb09-MetaGGA convergence problem
> 
> I'll install it and make the test.
> Just give me some little time please.
> 
> 
> On 04/07/2015 08:44 PM, plgong wrote:
> 
> > Dear pwscf_user,
> >     Recently, I used  the tb09 (Meta-GGA) in the version of QE5.1.2, but it aways did not converge.
> > The error is like, 
> >      'Error in routine cdiaghg (23):
> >      eigenvectors failed to converge'
> > 
> > I have performed too much tests on Ecutoff, k_points, degauss, as well as reduce mixing.  What should I do?
> > 
> > 
> > My input file is,
> > 
> > &CONTROL
> >                  calculation = 'scf' ,
> >                 restart_mode = 'from_scratch' ,
> >                       outdir = './tmp' ,
> >                   pseudo_dir = './' ,
> > verbosity='high',
> >                       prefix = 'graphene' ,
> >  /
> >  &SYSTEM
> >                        ibrav =0,
> >                          nat = 2
> >                         ntyp = 1,
> > celldm(1)=1.89,
> > ecutwfc= 60
> > input_dft='tb09'
> >                        nosym = .false. ,
> >                   tot_charge = 0.000000,
> >                  occupations = 'fixed', nbnd=24
> >  /
> >  &ELECTRONS
> >                     conv_thr = 1.D-7 ,
> >                  mixing_mode = 'plain' ,
> >                  mixing_beta = 0.1D0 , mixing_ndim=12
> >              diagonalization = 'cg' ,
> >  /
> >  &IONS
> >                 ion_dynamics = 'bfgs' ,
> >            pot_extrapolation = 'second_order' ,
> >            wfc_extrapolation = 'second_order' ,
> > /
> > ATOMIC_SPECIES
> >     Si   12.01000 Si.pz-vbc.UPF
> > K_POINTS automatic
> > 12 12 12 0 0 0
> > CELL_PARAMETERS
> >        0.000000000000000       2.715350000000000       2.715350000000000
> >        2.715350000000000      -0.000000000000001       2.715350000000000
> >        2.715350000000000       2.715349999999999      -0.000000000000000
> > ATOMIC_POSITIONS (crystal)
> >  Si   0.0000000000000000   0.0000000000000000   0.0000000000000000
> >  Si   0.2500000000000000   1.2500000000000002   0.2500000000000001
> > 
> > 
> > 
> > PL Gong
> > --
> > 
> > ====================================================
> > Addr: Institute of Solid State Physics, Chinese Academy of 
> > Sciences, Hefei, Anhui 230031, China
> > Tel: +86-551-65591591(office), 18756086113(cell phone)
> > Email: plgong at theory.issp.ac.cn
> > ========================================================================
> > 
> > 
> > 
> > 
> > 
> > _______________________________________________
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://pwscf.org/mailman/listinfo/pw_forum
> 
> -- 
> Éric Germaneau (艾海克), Specialist
> Center for High Performance Computing
> Shanghai Jiao Tong University
> Room 205 Network Center, 800 Dongchuan Road, Shanghai 200240 China
> Email:germaneau at sjtu.edu.cnMobi:+86-136-4161-6480 http://hpc.sjtu.edu.cn

--

====================================================
Addr: Institute of Solid State Physics, Chinese Academy of 
Sciences, Hefei, Anhui 230031, China
Tel: +86-551-65591591(office), 18756086113(cell phone)
Email: plgong at theory.issp.ac.cn
========================================================================