[Wien] some questions about LDA+U caculation of anatase

[白宇]

Dear Wien users:
Recently I had done some caculation about anatase TiO2 using LDA+U method. I followed Anisimov's way that add a 6eV potential
to Ti 3d orbit. But I could not get the correct result like his caculation which have a 3.2eV bandgap, while I have only 2.8eV.
Since he is using the LCAO basis, I wondered whether his U=6eV is suitable for out LAPW basises? Major input file is listed below.And at the same time I want to know whether the two Ti atoms in struct file which all have the same atom index have been added with the orb potential?
Please give me some suggestions on how i can get a more desirable result like a 3.2 eV bandgap?

PS: my SCF is ran under -ec 0.00005. Is the covergence too large?


anatase
B   LATTICE,NONEQUIV.ATOMS:  2141_I41/amd
MODE OF CALC=RELA unit=bohr
  7.223948  7.223948 18.164868 90.000000 90.000000 90.000000
ATOM  -1: X=0.00000000 Y=0.25000000 Z=0.87500000
          MULT= 2          ISPLIT=-2
      -1: X=0.00000000 Y=0.75000000 Z=0.12500000
Ti         NPT=  781  R0=0.00005000 RMT=    1.8000   Z: 22.0
LOCAL ROT MATRIX:    0.7071068-0.7071068 0.0000000
                     0.7071068 0.7071068 0.0000000
                     0.0000000 0.0000000 1.0000000
ATOM  -2: X=0.00000000 Y=0.25000000 Z=0.08271596
          MULT= 4          ISPLIT= 8
      -2: X=0.00000000 Y=0.75000000 Z=0.91728404
      -2: X=0.00000000 Y=0.75000000 Z=0.33271596
      -2: X=0.50000000 Y=0.75000000 Z=0.16728404
O          NPT=  781  R0=0.00003000 RMT=    1.6000   Z:  8.0
LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
                     0.0000000 1.0000000 0.0000000
                     0.0000000 0.0000000 1.0000000
  16      NUMBER OF SYMMETRY OPERATIONS
******************************************************************
indm:
-9.                      Emin cutoff energy
 1                       number of atoms for which density matrix is calculated
 1  1  2      index of 1st atom, number of L's, L1
 0 0           r-index, (l,s)index
*********************************************************************
inorb:
  1  1  0                     nmod, natorb, ipr
PRATT  1.0                    BROYD/PRATT, mixing
  1 1 2                          iatom nlorb, lorb
  1                              nsic 0..AFM, 1..SIC, 2..HFM
   0.44 0.01                      U J (Ry)