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本帖最后由 yika 于 2024-12-26 19:12 编辑
各位老师好,我现在在做一个吸附催化的过程,在对基底Bi-Bi2WO6-Co3O4进行结构优化的过程中,可能是由于初始初猜结构比较差或者体系的磁性,优化的力收敛速度极慢,在以下参数
ISTART = 0
ISPIN = 2
NWRITE = 2
ICHARG = 2
LREAL = A
ENCUT = 500
PREC = Accurate
LWAVE = .FALSE.
LCHARG = .FALSE.
ADDGRID= .TRUE.
NPAR = 4
ALGO = Fast
LSCALAPACK = .FALSE.
IVDW = 11
MAGMOM = 136*0.1 3.0 -3.0 -3.0 3.0 0 0 0 0 0 0 0 0 3.0 -3.0 -3.0 3.0 0 0 0 0 0 0 0 0 3.0 -3.0 -3.0 3.0 0 0 0 0 0 0 0 0 3.0 -3.0 -3.0 3.0 0 0 0 0 0 0 0 0 12*0 42*0
AMIX = 0.1
BMIX = 0.0001
AMIX MAG = 0.8
BMIX MAG = 0.0001
ISMEAR = 0
SIGMA = 0.05
NELM = 200
NELMIN = 6
EDIFF = 1E-06
GGA = PE
NSW = 200
IBRION = 2
ISIF = 2
EDIFFG = -2E-02
ISYM = 2
POTIM = 0.3
下优化了200步之后,离收敛标准相差还极大,最后10步的受力情况如下:
FORCES: max atom, RMS 0.799486 0.131053
FORCES: max atom, RMS 0.933182 0.155635
FORCES: max atom, RMS 0.639773 0.114698
FORCES: max atom, RMS 0.788533 0.113398
FORCES: max atom, RMS 0.920738 0.135086
FORCES: max atom, RMS 0.656356 0.110066
FORCES: max atom, RMS 0.895383 0.141489
FORCES: max atom, RMS 0.458867 0.100004
FORCES: max atom, RMS 1.126553 0.164146
FORCES: max atom, RMS 0.900801 0.127245
于是,此后我修改IBRION=1,EDIFF=1E-08(其他参数不变)之后继续优化,200步后依然不收敛,最后10步的受力情况如下:
FORCES: max atom, RMS 0.173561 0.041597
FORCES: max atom, RMS 0.166215 0.041180
FORCES: max atom, RMS 0.166240 0.041033
FORCES: max atom, RMS 0.167760 0.041015
FORCES: max atom, RMS 0.166119 0.040868
FORCES: max atom, RMS 0.168121 0.041382
FORCES: max atom, RMS 0.165275 0.041002
FORCES: max atom, RMS 0.163527 0.040948
FORCES: max atom, RMS 0.165943 0.040887
FORCES: max atom, RMS 0.165988 0.040898
想求助一下接下来我应该怎么做比较好,是不是在这个基础上将IBRION继续修改为2,同时参数调整为POTIM = 0.5,EDIFFG = -0.05再优化看看之后再改成QN优化到EDIFFG=-0.02。还是说有其他效率更高的方法,我之前有看到帖子说IBRION = 3对初猜较差的结构优化更适合,不知是不是这样。
我是第一次做这样的任务,如果有问题没有说清楚,还请多多包涵。
附件是我目前的CONTCAR
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CONTCAR
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