vasp计算四方相P42/nmc HfO2声子频率过低，晶格常数偏高，如何解决？

crystalcat

使用了PAW_PBE （GGA）赝势， Hf_sv，O
EDIFF=1E-08，EDIFFG=-0.001，已经充分迭代到收敛，kspace取0.03。
声子计算采用有限差分方法IBRION =  6
最低声子频率48cm-1远低于参考文献给出的一百多cm-1,不知道如何解决？是什么引起？
不胜感激。

INCAR.relax
Global Parameters
ISTART =  1            (Read existing wavefunction, if there)
ISPIN  =  1            (Non-Spin polarised DFT)
# ICHARG =  11         (Non-self-consistent: GGA/LDA band structures)
LREAL  = .FALSE.       (Projection operators: automatic)
ENCUT  =  520        (Cut-off energy for plane wave basis set, in eV)
# PREC   =  Accurate   (Precision level: Normal or Accurate, set Accurate when perform structure lattice relaxation calculation)
LWAVE  = .TRUE.        (Write WAVECAR or not)
LCHARG = .TRUE.        (Write CHGCAR or not)
ADDGRID= .TRUE.        (Increase grid, helps GGA convergence)
LASPH  = .TRUE.        (Give more accurate total energies and band structure calculations)
PREC   = Accurate      (Accurate strictly avoids any aliasing or wrap around errors)
# LVTOT  = .TRUE.      (Write total electrostatic potential into LOCPOT or not)
# LVHAR  = .TRUE.      (Write ionic + Hartree electrostatic potential into LOCPOT or not)
# NELECT =             (No. of electrons: charged cells, be careful)
# LPLANE = .TRUE.      (Real space distribution, supercells)
# NWRITE = 2           (Medium-level output)
# KPAR   = 2           (Divides k-grid into separate groups)
# NGXF    = 300        (FFT grid mesh density for nice charge/potential plots)
# NGYF    = 300        (FFT grid mesh density for nice charge/potential plots)
# NGZF    = 300        (FFT grid mesh density for nice charge/potential plots)
EDIFF = 1E-08
Lattice Relaxation
NSW    =  300          (number of ionic steps)
ISMEAR =  0            (gaussian smearing method )
SIGMA  =  0.05         (please check the width of the smearing)
IBRION =  2            (Algorithm: 0-MD, 1-Quasi-New, 2-CG)
ISIF   =  3            (optimize atomic coordinates and lattice parameters)
EDIFFG = -1E-03      (Ionic convergence, eV/A)

INCAR.phonon
ISMEAR =  0            (Gaussian smearing)
SIGMA  =  0.01         (Smearing value in eV)
EDIFF  =  1E-08        (SCF energy convergence, in eV)
PREC   =  Accurate     (Precision level)
ENCUT  =  520        (Cut-off energy for plane wave basis set, in eV)
IALGO  =  38           (Davidson block iteration scheme)
LREAL  = .FALSE.       (Projection operators: false)
LWAVE  = .FALSE.       (Write WAVECAR or not)
LCHARG = .FALSE.       (Write CHGCAR or not)
ADDGRID= .TRUE.        (Increase grid, helps GGA convergence)
IBRION =  6            (Calculate phonon frequencies using finite differences approach)
LPHON_DISPERSION = T   (Calculate phonon dispersion along the q-point path supplied in file QPOINTS)
PHON_NWRITE = -3       (Both phonon eigenvectors and phonon frequencies are written for each q point)



POSCAR:
Hf2 O4                                 
   1.00000000000000     
     3.5941944686576677    0.0000000000000000    0.0000000000000000
     0.0000000000000000    3.5941944686576677    0.0000000000000000
     0.0000000000000000    0.0000000000000000    5.2305425368624849
   Hf   O
     2     4
Direct
  0.5000000000000000  0.5000000000000000  0.5000000000000000
  0.0000000000000000  0.0000000000000000  0.0000000000000000
  0.0000000000000000  0.5000000000000000  0.6957736386243809
  0.5000000000000000  0.0000000000000000  0.8042263613756191
  0.5000000000000000  0.0000000000000000  0.3042263913756216
  0.0000000000000000  0.5000000000000000  0.1957736086243784

  0.00000000E+00  0.00000000E+00  0.00000000E+00
  0.00000000E+00  0.00000000E+00  0.00000000E+00
  0.00000000E+00  0.00000000E+00  0.00000000E+00
  0.00000000E+00  0.00000000E+00  0.00000000E+00
  0.00000000E+00  0.00000000E+00  0.00000000E+00
  0.00000000E+00  0.00000000E+00  0.00000000E+00

伽马点最低光学支频率：

  14 f  =    1.453087 THz     9.130013 2PiTHz   48.469753 cm-1     6.009481 meV
             X         Y         Z           dx          dy          dz
      1.797097  1.797097  2.615271     0.008617    0.208536   -0.000000  
      0.000000  0.000000  0.000000     0.008617    0.208536   -0.000000  
      0.000000  1.797097  3.639274    -0.000211   -0.675007   -0.000000  
      1.797097  0.000000  4.206540    -0.000211   -0.675007   -0.000000  
      1.797097  0.000000  1.591269    -0.027894   -0.005101    0.000000  
      0.000000  1.797097  1.024002    -0.027894   -0.005101   -0.000000  

  15 f  =    1.453087 THz     9.130013 2PiTHz   48.469753 cm-1     6.009481 meV
             X         Y         Z           dx          dy          dz
      1.797097  1.797097  2.615271     0.208536   -0.008617   -0.000000  
      0.000000  0.000000  0.000000     0.208536   -0.008617   -0.000000  
      0.000000  1.797097  3.639274    -0.005101    0.027894   -0.000000  
      1.797097  0.000000  4.206540    -0.005101    0.027894    0.000000  
      1.797097  0.000000  1.591269    -0.675007    0.000211   -0.000000  
      0.000000  1.797097  1.024002    -0.675007    0.000211   -0.000000