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标题: 高熵合金结构优化：VASP软件中的DFT+U参数如何设置 [打印本页]

作者
Author: 839763262 时间: 2024-3-24 12:14
标题: 高熵合金结构优化：VASP软件中的DFT+U参数如何设置
我按照网上设置的DFT+U，结果发现不收敛。高熵合金里面的元素：Al Cr Ni Co Fe Cu，每种元素有8个，总共48个原子的超胞模型
其中INCAR的设置：
ISTART =  1          (Read existing wavefunction; if there)
ISPIN =  2          (Spin polarised DFT)
LREAL  = .FALSE.    (Projection operators: automatic)
ENCUT  =  450       (Cut-off energy for plane wave basis set, in eV)
PREC =  Normal    (Precision level)
ADDGRID= .TRUE.       (Increase grid; helps GGA convergence)
Electronic Relaxation
ISMEAR =  0          (Gaussian smearing; metals:1)
SIGMA  =  0.05       (Smearing value in eV; metals:0.2)
NELM =  100          (Max electronic SCF steps)
NELMIN =  6          (Min electronic SCF steps)
EDIFF  =  1E-03       (SCF energy convergence; in eV)
GGA  =  PE          (PBEsol exchange-correlation)
Ionic Relaxation
NSW =  500       (Max ionic steps)
IBRION =  2          (Algorithm: 0-MD; 1-Quasi-New; 2-CG)
ISIF =  2          (Stress/relaxation: 2-Ions, 3-Shape/Ions/V, 4-Shape/Ions)
EDIFFG = -1E-02       (Ionic convergence; eV/AA)
# ISYM =  2          (Symmetry: 0=none; 2=GGA; 3=hybrids)
LDAU = .TRUE.
LDAUTYPE = 2
LDAUL = -1 3
LDAUU = 0.0 5.5
LDAUJ = 0.0 0.5
LMAXMIX = 6
LREAL=Auto
NPAR=4

以下是OSZICAR输出的能量：
31 F= -.28554903E+03 E0= -.28552051E+03  d E =-.664931E-01  mag= 33.3287
  32 F= -.28560089E+03 E0= -.28557247E+03  d E =-.518547E-01  mag= 33.2627
  33 F= -.28565590E+03 E0= -.28562780E+03  d E =-.106872E+00  mag= 33.1065
  34 F= -.28561081E+03 E0= -.28558326E+03  d E =-.617736E-01  mag= 32.8603
  35 F= -.28566550E+03 E0= -.28563763E+03  d E =-.116472E+00  mag= 32.9754
  36 F= -.28571853E+03 E0= -.28569097E+03  d E =-.530240E-01  mag= 32.9651
  37 F= -.28586519E+03 E0= -.28583821E+03  d E =-.199684E+00  mag= 32.8567
  38 F= -.28592004E+03 E0= -.28589316E+03  d E =-.254537E+00  mag= 32.6356
  39 F= -.28596247E+03 E0= -.28593587E+03  d E =-.296964E+00  mag= 32.7170
  40 F= -.28608585E+03 E0= -.28605925E+03  d E =-.123378E+00  mag= 32.7026
  41 F= -.28600125E+03 E0= -.28597407E+03  d E =-.387796E-01  mag= 32.6088
  42 F= -.28615448E+03 E0= -.28612774E+03  d E =-.192014E+00  mag= 32.6683
  43 F= -.28616345E+03 E0= -.28613669E+03  d E =-.200979E+00  mag= 32.6600
  44 F= -.28626596E+03 E0= -.28623917E+03  d E =-.102512E+00  mag= 32.6556

每一个电子步需要计算70秒左右
每一个离子步需要计算600秒左右

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