contradict results of the magnetic moment as the ALGO = All

[Kun Tao]

Hi all,

I want to do some calculations using the ALGO = All, when I did scf, I obtained the magnetic moment of the Cu = 0.672, however, when I performed the band structure calculations, I got the magnetic moment of the same Cu is only 0.032! Could you give me some advices?

Attached below is the INCAR for scf:

Code: Select all

   ISTART = 0
   NWRITE = 2       : verbosity

 # ICHARG = 11
   ENCUT = 520
   ADDGRID = .TRUE.
   PREC   = accurate     : accuracy
   NELM   = 500     : maximum number of SCF iterations
   NELMIN =  8      : minimal number of SCF iterations
   NELMDL = -6      : number of non-SCF iterations
   EDIFF  = 1E-6    : criterion for SCF convergence
   ISMEAR = 0       : Methfessel-Paxton smearing
   SIGMA  = 0.05    : sigma for smearing
    NPAR   = 8
 
   GGA = PS
   GGA_COMPAT = .FALSE.
   VOSKOWN = 1

  # IALGO = 48
  ALGO = All

   ISPIN  = 2
   MAGMOM = 112*0 24*0 38*0 1 1
 
  # LNONCOLLINEAR= .TRUE.

   LORBIT = 11

   AMIX = 0.005
   BMIX  = 0.0001
   AMIX_MAG = 0.01
   BMIX_MAG = 0.0001

   LWAVE   =  .FALSE.
  # LCHARG  =  .FALSE.
  LREAL = Auto
   ISYM = -1

 ####################################
# LDA+U
  LDAU=.TRUE.                                     # AFLOW LSDA+U
# LDAU_SPECIES=B Lu                              # LDAU species
   LDAUL=-1 -1 -1 2           # l-quantum number for which the on site interaction is added (Default 2) automatic LDAUL tab    le
   LDAUU=0 0 0 7.0                                  # UEFF parameter. Automatic LDAUU table
   LDAUJ=0 0 0 0.7                                 # J parameter (if used). Automatic LDAUJ table
   LDAUTYPE=2                                      # Type of LDA+U.
   LDAUPRINT=0                                     # Controls verbosity of the L(S)DA+U module. (Default 0) # AFLOW LSDA+U
 ####################################
# Ionic Relaxation
   NSW    = 0        :  maximum number of ionic steps
   EDIFFG = -1.0E-2  :  maximal residual force in eV/Ang
   IBRION = -1        :  quasi-Newton optimization
   ISIF   = 2        :  optimize ions, cell shape and volume

and when I did the band structure calculations, I only changed the ICHARG = 1 with ICHARG = 11.

and the KPOINTS for scf calculation is:

Code: Select all

K-Spacing Value to Generate K-Mesh: 0.040
  0
 Gamma
 1   1   3
 0.0  0.0  0.0

and the KPOINTS for band structure calculation is:

Code: Select all

   kpoint
      5
   Line-Mode
   Reciprocal
      0.0000000000   0.0000000000   0.0000000000     GAMMA
      0.5000000000   0.0000000000   0.0000000000     M
  
      0.5000000000   0.0000000000   0.0000000000     M
      0.3333333333   0.3333333333   0.0000000000     K
 
     0.3333333333   0.3333333333   0.0000000000     K
     0.0000000000   0.0000000000   0.0000000000     GAMMA
 
     0.0000000000   0.0000000000   0.0000000000     GAMMA
     0.0000000000   0.0000000000   0.5000000000     A
 
     0.0000000000   0.0000000000   0.5000000000     A
     0.5000000000   0.0000000000   0.5000000000     L

[merzuk.kaltak]

Dear Kun Tao,

would you please provide the other input files (POSCAR, POTCAR) as well?
It would be helpful to obtain also the corresponding stdout and OUTCARs of the runs. Also, please let us know which vasp version you are running.

[Kun Tao]

Dear merzuk.kaltak ,

I am using the vasp5.4.4. Attached below is the OUTCAR, the POSCAR and the POTCAR files, please check up.

Best regards,
Kun Tao

[Kun Tao]

Hi all.

any suggestions?

With regards,
Kun Tao

[merzuk.kaltak]

Dear Kun Tao,

The local magnetic moment written to OUTCAR is obtained as a volume integral over the first Brillouin zone.
In the first step you essentially use a set of k-points that is chosen by vasp such to obtain a good estimate for the volume integral over the first Brillouin zone.

Once, you switched to line-mode to plot the band structure along a specific path in the Brillouin zone,
you loose the capability of the k-point mesh to integrate over the Brillouin zone. Therefore, the magnetic moments in a line-mode calculation are meaningless.

[Kun Tao]

Dear merzuk.kaltak,

Thank you for your reply， now I got it.

But, the problem is that if the magnetic moments in a line-mode calculation are meaningless, then what about the band structure？ Does it means that we do have the same band structure no matter what magnetic moment that we have?

Best regards,
Kun Tao

[merzuk.kaltak]

Please ignore the magnetic moment written in the OUTCAR for a line-mode calculation.
These values are not correct.

The band structure is obtained by interpolating the charge density between the k-points given in the first calculation and is thus also correct for magnetic systems.