VASP自旋轨道耦合计算错误汇总

VASP自旋轨道耦合计算错误汇总

静态计算时，报错：

VERY BAD NEWS!Internal内部error in subroutine子程序IBZKPT:

Reciprocal倒数的lattice and k-lattice belong to different class of lattices.Often results are still useful (48)

INCAR参数设置：

对策：根据所用集群，修改INCAR中NPAR。将NPAR=4变成NPAR=1，已解决！

错误：sub space matrix类错误

报错：静态和能带计算中出现警告：WARNING:Sub-Space-Matrix is not hermitian共轭in DAV

结构优化出现错误：

WARNING:Sub-Space-Matrix is not hermitian in DAV4-4.681828688433112E-002

对策：通过将默认AMIX=0.4，修改成AMIX=0.2（或0.3），问题得以解决。

以下是类似的错误：

WARNING:Sub-Space-Matrix is not hermitian in rmm-3.00000000000000

RMM:22-0.167633596124E+02-0.57393E+00-0.44312E-0113260.221E+00BRMIX:

very serious problems the old and the new charge density differ old charge density:28.00003new28.060930.111E+00

错误：

WARNING:Sub-Space-Matrix is not hermitian in rmm-42.5000000000000

ERROR FEXCP:supplied Exchange-correletion table is too small,maximal index:4794

错误：结构优化Bi2Te3时，log文件：

WARNING in EDDIAG:sub space matrix is not hermitian1-0.199E+01

RMM:2000.179366581305E+01-0.10588E-01-0.14220E+007180.261E-01

BRMIX:very serious problems the old and the new charge density differ old charge density:56.00230new124.70394 66F=0.17936658E+01E0=0.18295246E+01d E=0.557217E-02

curvature:0.00expect dE=0.000E+00dE for cont linesearch0.000E+00

ZBRENT:fatal error in bracketing

please rerun with smaller EDIFF,or copy CONTCAR to POSCAR and continue

但是，将CONTCAR拷贝成POSCAR，接着算静态没有报错，这样算出来的结果有问题吗？

对策1：用这个CONTCAR拷贝成POSCAR重新做一次结构优化，看是否达到优化精度！

对策2：用这个CONTCAR拷贝成POSCAR，并且修改EDIFF（目前参数EDIFF=1E-6）,默认为10-4

错误：

WARNING:Sub-Space-Matrix is not hermitian in DAV1-7.626640664998020E-003

网上参考解决方案：

对策1：减小POTIM:IBRION=0，标准分子动力学模拟。通过POTIM控制步长。

POTIM：当IBRION=1,2或3时，是力的一个缩放常数（相当于确定原子每步移动的大小），默认值为0.5。

对策2：改IBRION=1，采用准牛顿算法来优化原子的位置。

原IBRION=2，采用共轭梯度算法来优化原子的位置

对策3：修改ISMEAR

对策4：换成CG弛豫（共轭梯度算法）IBRION=2(决定结构优化过程中，原子如何移动或弛豫)

IBRION=2离子是否运动，1不运动但做NSW外循环。0动力学模拟，1准牛顿法离子弛豫

2CG法离子弛豫，3采用衰减二阶运动方程离子弛豫，

INCARrelax中设置IBRION=2，未解决！

对策5：用的CG算符，出现的错误是CG算符不能算，在INCAR中加上IALG=Fast（电子优化采用blocked Davidson 方法[IALGO=38:IALG=Normal]和RMM-DIIS算法[IALGO=48:IALG=Very_Fast]混合）试一试

IALG=Fast(两种方法混用)

IALG=Very_Fast(等价于IALGO=48)

IALG=Normal（等价于IALGO=38）

INCAR中加上IALG=Fast已解决！（1QL、2QL已解决，3QL以上未解决）

VASP FORUM:the error is due to a LAPCK call(ZHEGV):ZHEGV computes all the eigenvalues本征值,and optionally随意地,the eigenvectors of a complex generalized Hermitian-definite eigenproblem.

there may be several reasons for that error:

1)the RMM-DIIS diagonalisation algorithm is not stable for your specific setup of the calculation.-->use ALGO=Normal (blocked Davidson)or ALGO=Fast(5steps blocked Davidson,RMM-DIIS)

用ALGO=Normal IALGO=48或者ALGO=Fast

2)

a)maybe your input geometry was not reasonable(error occurs at the very first ionic step,please have a look for the geometry data of your run in OUTCAR)or

b)the last ionic relaxation step lead to an unreasonable geometry(compare the input and output geometries of the last ionic relaxation steps in XDATCAR).

In that case(2b)it can be helpful to-->switch to a different relaxation algorithm(IBRION-tag)-->reduce the step size of the first step by setting POTIM smaller than the default value

改变IBRION，减少步长POTIM

3)The installation of the LAPACK on your machine was not done properly:use the LAPACK which is delivered with the code (vasp.4.lib/lapack_double.o)

4)If the error persist although you switched to the Davidson algorithm:on some architectures(especially SGI)some LAPACK routines are not working properly.However,it is possible to avoid the usage of the ZHEGV subroutine by commenting the line #define USE_ZHEEVX in davidson.F,subrot.F,and wavpre_noio.F and recompiling VASP.

关于Mixing方法的调试：

针对这类错误：

DAV:13-0.242323773333E+030.98155E+02-0.87140E+01488320.949E+01BRMIX:very serious problems the old and the new charge density differ old charge density:252.00012new252.299790.809E+01

WARNING:Sub-Space-Matrix is not hermitian in DAV90.133520549894753

.....

解决办法只需调整AMIX,BMIX的值，把他们设置小一些。

Mixing方法：

IMIX=type of mixing混合、混频，AMIX=linear mixing parameter，AMIN=minimal mixing parameter,

BMIX=cutoff wave vector for Kerker mixing scheme,AMIX_MAG=linear mixing parameter for magnetization,

BMIX_MAG=cutoff wave vector for Kerker mixing scheme for mag,WC=weight factor for each step in Broyden mixing scheme,

INIMIX=type of initial for each step in Broyden mixing scheme,MIXPRE=type of preconditioning in Broyden mixing scheme,

MAXMIX=maximum number steps stored in Broyden mixer.

一般采用其默认值，除非在电子迭代难以收敛的情况，才手动设置AMIX和BMIX等参数值。】

对策：grep AMIX OUTCAR

AMIX=0.40;BMIX= 1.00

AMIX_MAG= 1.60;BMIX_MAG= 1.00

initial mixing is a Kerker type mixing with AMIX=0.4000and BMIX=1.0000