V ASP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：W ARNING: Sub-Space-Matrix is not hermitian共轭in DA V结构优化出现错误：
WARNING: Sub-Space-Matrix is not hermitian in DA V 4 -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-01 1326 0.221E+00BRMIX:
very serious problems the old and the new charge density differ old charge density: 28.00003 new 28.06093 0.111E+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 hermitian 1 -0.199E+01RMM: 200 0.179366581305E+01 -0.10588E-01 -0.14220E+00 718 0.261E-01
BRMIX: very serious problems the old and the new charge density differ old charge density: 56.00230 new 124.70394 66 F=0.17936658E+01 E0= 0.18295246E+01 d E =0.557217E-02
curvature: 0.00 expect dE= 0.000E+00 dE for cont linesearch 0.000E+00ZBRENT: 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 DA V 1 -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2 CG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）
V ASP 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 (5 steps blocked Davidson, RMM-DIIS)⽤ALGO=Normal IALGO=48 或者ALGO=Fast2)
a) maybe your input geometry was not reasonable (error occurs at the very first ionic step, please have a look for thegeometry 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 ionicrelaxation steps in XDA TCAR).
In that case (2b) it can be helpful to --> switch to a different relaxation algorithm (IBRION-tag) --> reduce the step size of thefirst 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 thecode (vasp.4.lib/lapack_double.o)
4) If the error persist although you switched to the Davidson algorithm: on some architectures (especially SGI) someLAPACK routines are not working properly. However, it is possible to avoid the usage of the ZHEGV subroutine bycommenting the line #define USE_ZHEEVX in davidson.F, subrot.F, and wavpre_noio.F and recompiling V ASP.关于Mixing⽅法的调试：针对这类错误：
DA V: 13 -0.242323773333E+03 0.98155E+02 -0.87140E+01 48832 0.949E+01BRMIX: very serious problems the old andthe new charge density differ old charge density: 252.00012 new 252.29979 0.809E+01W ARNING: Sub-Space-Matrix is not hermitian in DA V 9 0.133520549894753.....
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 mixingscheme,
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 OUTCARAMIX = 0.40; BMIX = 1.00
AMIX_MAG = 1.60; BMIX_MAG = 1.00
initial mixing is a Kerker type mixing with AMIX = 0.4000 and BMIX = 1.0000设置：
初始值收敛值结果
AMIX =0.0100；BMIX =0.0001 AMIX = 0.01; BMIX = 0.00 计算⽆误AMIX = 0.1000；BMIX = 0.0010 AMIX = 0.10; BMIX = 0.00 计算⽆误AMIX =0.20; BMIX = 0.01 AMIX =0.20; BMIX = 0.01 计算⽆误AMIX=0.2、BMIX=0.001 AMIX=0.2、BMIX=0.001 计算⽆误AMIX=0.3、BMIX=0.1 AMIX=0.3、BMIX=0.1 计算⽆误
AMIX=0.4 AMIX = 0.40; BMIX = 1.00 静态log: WARNING in EDDRMM: call toZHEGV failed, returncode = 6 3 **,能带⼀样
AMIX=0.02 AMIX = 0.02; BMIX = 1.00 计算⽆误
AMIX=0.1 AMIX = 0.10; BMIX = 1.00 静态log: WARNING in EDDRMM: call toZHEGV failed, returncode = 6 3 **,能带⼀样
AMIX=0.3 AMIX = 0.30; BMIX = 1.00 静态log: WARNING in EDDRMM: call toZHEGV failed, returncode = 6 3 **,能带⼀样
BMIX=0.0001 AMIX = 0.40; BMIX = 0.00 计算⽆误以上参数设置，得到的能带图都⼀样，如下图:
综上：设置AMIX=0.2（或0.3）,BMIX默认（省事，等于1.0），可以保证计算过程⽆误。还需进⼀步调整其他参数，算出正确的能带。
警告：算1QL弛豫、静态、能带时，都有这个提⽰：
ADVICE TO THIS USER RUNNING 'V ASP/V AMP' (HEAR YOUR MASTER'S VOICE ...): You have a (more or less)'small supercell' and for smaller cells it is recommended to use the reciprocal-space projection scheme! The real spaceoptimization is not efficient for small cells and it is also less accurate ... Therefore set LREAL=.FALSE. in the INCAR file
对策：对于较⼩的晶胞（原⼦数⼩于20），设置LREAL=.FALSE.，计算结果⽐较精确。⽽对于较⼤的晶胞，设置LREAL=Auto，这样计算速度⽐较快。本体系含原⼦5个，INCAR中LREAL=Auto。设置所有INCAR中的LREAL=.FALSE.，重新算⼀遍。
对于1QL 2QL 3QL原⼦数分别为5、10、15，LREAL=.False.对于4QL 5QL 6QL原⼦数分别为20、25、30，LREAL=Auto⾃旋轨道耦合计算时，静态和能带计算中出现的错误：
ERROR: non collinear calculations require that V ASP is compiled without the flag -DNGXhalf and -DNGZhalf分析：V ASP⼿册中关于⾃旋轨道耦合计算的描述（翻译版）：
⾮线性计算和⾃旋轨道耦合：旋量是由Georg Kresse 在V ASP 代码中引⼊的。这个代码是由David Hobbs 编写，⽤于处理⾮线性磁结构。⾃旋轨道耦合计算是由Olivier Lebacq and Georg Kresse 共同实现的。只有V ASP4.5以上的版本才⽀持旋量的计算。
在INCAR 中设置LNONCOLLINEAR=.TRUE.允许执⾏完全⾮线性磁结构的计算。V ASP 有能⼒读⼊之前⾮磁或⾮线性计算得到的W A VECAR 和 CHGCAR ⽂件，然⽽它不可能扭转局域在指定原⼦处的磁场。因此在实际操作中，我们推荐分两步执⾏⾮线性计算：
第⼀步，计算计算⾮磁性基态，产⽣W A VECAR 和CHGCAR ⽂件。
第⼆步，读⼊W A VECAR 和CHGCAR ⽂件，通过设置MAGMOM 参数，提供初始的磁矩。对于⾮线性设置，在MAGMOM这⼀⾏，每个离⼦必须设置三个值。这三项分别对应每个离⼦在x,y,z ⽅向的初始局域磁矩值。MAGMOM = 1 0 0 0 1 0
这⼀⾏，给第⼀个原⼦赋予的初始磁矩值沿x ⽅向，第⼆个原⼦的初始磁矩值沿y ⽅向。
注意：只有在 ICHARG=2（即不读⼊之前CHGCAR 的情况）或者CHGCAR ⽂件中只包含电荷但是不包括磁密度数据的情况（即之前那⼀步进⾏了⾮磁的计算）下，才需要通过MAGMOM 设定初始磁矩值。LSORBIT-tag Supported as of VASP.4.5.
【设置LSORBIT=.TRUE.表⽰计算⾃旋轨道耦合，并附带⾃动设置了LNONCOLLINEAR= .TRUE.】
LSORBIT=.TRUE.只能⽤于PAW 赝势，不能⽤于超软赝势。如果不考虑⾃选轨道耦合，则能量不依赖磁矩的⽅向，也就是说，旋转所有的磁矩以同⼀个⾓度，让它们拥有相等的能量。不考虑⾃选轨道耦合的时候，不需要定义⾃旋量⼦化坐标。开启⾃旋轨道耦合设置以下参数：LSORBIT = .TRUE.
SAXIS = s_x s_y s_z ( ⾃旋量⼦化轴，默认值 SAXIS= (0+,0,1))GGA_COMPA T = .FALSE. ! 应⽤球⾯截断能到梯度场
其中SAXIS 默认= (0+,0,1)（0+表⽰沿x 轴⽅向⼀个⽆穷⼩的正数）。当需要计算亚meV 能量尺度的微⼩能量差异（⼀般指磁各向异性计算的情况）时，需要设置GGA_COMPA T 这个参数。现在所有关于坐标轴 (Sx,Sy,Sz)的磁矩都给出来了，我们采⽤V ASP 中给出关于这个坐标轴所有磁矩和⾃旋状量⼦读写惯例。
这包括INCAR ⽂件中的MAGMOM ⾏，OUTCAR 和PROCAR ⽂件中的总和局域磁矩，W A VECAR ⽂件中的类⾃旋轨道，CHGCAR ⽂件中的磁密度。笛卡尔坐标系中的磁分量由以下等式得到：axis zaxis x z axis zaxis y x y axis z
axis y axis x x m m m m m m m m m m m )cos()sin()sin()sin()cos()sin()cos()cos(*)sin()sin()cos()cos(ββαβααβαβααβ+-=++=+-=
其中，maxis 是外部可见的磁矩值，此处的α是SAXIS ⽮量(sx, sy, sz)和笛卡尔坐标x 轴的夹⾓，β是SAXIS ⽮量和笛卡尔坐标z 轴的夹⾓,z y x x y s s s a s s a ||tan ,tan
22+==βα, 以下等式得到逆变化：
z y x axis y x axis z y x axis m m m m m m m m m m m z yx
)cos()sin()sin()cos()sin()cos()sin()sin()sin()cos()cos()cos(βαβαβααβαβαβ++=+-=++=
不难看出，默认值(sx, sy, sz) = (0+,0,1)，两个⾓度都是0，即β=0和α=0。在这种情况下，内部转换简单地等于外部地转换：axis z z axis y y axis x x m m m m m m ===,,，第⼆种重要的情况，是0=axis x m 和0=axis y m ，在这种情况下：222222
/)(cos /)cos(*)sin(z y x z axis z axis x z y z
y z axis z axis z x s s s s m m m m s s s s m m m x ++===++==βαβ
因此现在磁矩是平⾏于SAXIS ⽮量。这样有两种⽅式去旋转⾃旋到任意⽅向，即通过改变初始的磁矩MAGMOM 或改变SAXIS。为了给计算赋予平⾏于⼀个选定的⽮量(x,y,z)的初始磁矩，可以通过设定（假定是单原⼦原胞）：MAGMOM = x yz !局域磁矩x y z
SAXIS = 0 0 1 ! 量⼦轴平⾏于z轴或者
MAGMOM = 0 0 total_magnetic_moment ! 局域磁矩平⾏于SAXISSAXIS = x y z ! 量⼦轴平⾏于⽮量(x,y,z)
两种设置都必须在相同能量的标准/辐射（原则、根源）场，但是要实现第⼆种⽅法，通常更加精确。第⼆种⽅法，也允许读⼊之前存在的W A VECAR⽂件（由线性计算还是⾮线性计算产⽣的都可以），然后继续⽤⼀个不同的⾃旋⽅向计算。当读⼊⼀个⾮线性W A VECAR⽂件，⾃旋假定平⾏于SAXIS（因此V ASP将仅仅输出⼀个z轴⽅向的磁矩）。推荐计算磁各项异性的步骤如下：
先做线性计算，得到⼀个W A VECAR和CHGCAR⽂件。加⼊以下参数：LSORBIT = .TRUE.
ICHARG = 11 ! ⾮⾃洽计算, 读⼊CHGCAR
LMAXMIX = 4 ! 对于d电⼦元素设置LMAXMIX=4, f电⼦元素设置LMAXMIX = 6! 在线性计算中，需要设置LMAXMIXSAXIS = x y z ! 磁场的⽅向NBANDS = 2 * 线性计算能带数
GGA_COMPA T = .FALSE. ! 在梯度场中应⽤球⾯截断能
V ASP读⼊WA VECAR和CHGCAR⽂件，将⾃旋量⼦轴对齐SAXIS⽮量，这意味着现在磁场平⾏于SAXIS⽮量，执⾏⾮线性计算。通过⽐较不同⽅向的能量，可以确定磁各向异性。请记住，原则上，在V ASP中⼀个完全地⾃洽计算(ICHARG=1)也是有可能的，但是这种情况将会允许⾃旋波函数从它们的初始值旋转到平⾏于SAXIS⽮量，直到获得正确的基态，也就是，直到磁矩平⾏于易磁化轴。实际操作中，这种旋转⾮常缓慢，直到⾃旋获得少量能量重新定位。因此，如果收敛标准太精确，完全地⾃洽计算可以得到⼀个⽐较合理的结果（我们实验过的⼏种⾃洽计算都没有问题。）要⾮常⼩⼼对称性。我们建议选择计算⾃旋轨道耦合时，完全关掉对称性(ISYM=0)。通常会从⼀个⾃旋⽅向到另⼀个⾃旋⽅向k点的设置会发⽣改变，进⽽恶化转换的结果（如果k点改变WA VECAR将不会被正确地重新读取）。GGA_COMPA T 通常需要，应该被设置，因为磁各向异性能量通常需要精确到亚meV数量级。
当计算⾃旋轨道耦合，特别是磁各向异性时通常需要⾮常⼩⼼：能量差异⾮常⼩，k点的收敛冗长⽽且缓慢，需要耗费⼤量的计算时间。此外，这⼀特征--尽管长期存在于V ASP中--在最新的版本中依然存在，你可以尝试频繁地升级发现这⼀点。不敢保证，你的结果是有⽤的！此处根据README⽂件做了⼀个⼩⼩的总结：
20.11.2003: 提出的GGA程序轻微的破坏了⾮正交体系晶胞的对称型。球⾯截断能应⽤于梯度及互逆空间中的所有中间结果。GGA引起的轻微的改变（通常每个原⼦0.1 meV），却对磁各项异性很重要。
05.12.2003: 继续...现在V ASP.4.6默认旧的⾏为GGA_COMPA T=.TRUE.，新的⾏为将可以通过在INACR中设置GGA_COMPA T=.FALSE.得到。
12.08.2003: 主要的错误出现在symmetry.F 和paw.F：⾮线性计算的对称性例程没有正确的执⾏。
如果你阅读了以上内容，就会意识到在V ASP.4.6和V ASP.5.2版本中进⾏⾮线性计算推荐设置GGA_COMPA T=.FALSE.，这样可以提升GGA计算的数值精度。
VASP: Non-collinear calculations and spin orbit coupling : Spinors旋量were included by Georg Kresse in the VASP code.The code required for the treatment处理of non-collinear magnetic structures was written by David Hobbs, and spin-orbitcoupling was implemented实施、执⾏by Olivier Lebacq and Georg Kresse. Spinors are only supported as of VASP.4.5.Subsections：分段、⼦章节、下⼀级栏⽬LNONCOLLINEAR-tagSupported⽀持as of VASP.4.5.
Setting LNONCOLLINEAR=.TRUE. in the INCAR file allows to perform fully non-collinear magnetic structure calculations.VASP is capable 有能⼒的 of reading WAVECAR and CHGCAR files from previous 之前的 non-magnetic ⾮磁 or collinear线性 calculations, it is however not possible to rotate 旋转、转动 the magnetic field locally on selected atoms.Hence 因此, in practice 在实践中, we recommend 推荐 to perform non-collinear calculations in two steps:First, calculate the non magnetic groundstate 基态 and generate a W A VECAR and CHGCAR file.
Second, read the W A VECAR and CHGCAR file, and supply 提供 initial magnetic moments by means of the MAGMOM tag(compare Sec. 6.13). For a non-collinear setup, three values must be supplied for each ion in the MAGMOM line. The threeentries correspond to the initial local magnetic moment for each ion in x, y and z direction respectively. The lineMAGMOM = 1 0 0 0 1 0
Initialises 赋初值 the magnetic moment on the first atom in the x-direction, and on the second atom in the y direction. Mind,that the MAGMOM line supplies initial magnetic moments only if ICHARG=2, or if the CHGCAR file contains only charge butno magnetisation density.
LSORBIT=.TRUE. Switches 接通、开启 on spin-orbit coupling and automatically sets LNONCOLLINEAR= .TRUE..This option 选项、选择 works only for PAW potentials and is not supported for ultrasoft pseudopotentials. If spin-orbit
coupling is not included, the energy does not depend on 依赖 the direction of the magnetic moment, i.e.也就是说 rotating 旋转 all magnetic moments 磁矩 by the same angle results exactly in the same energy. Hence 因此 there is no need to definethe spin quantization axis ⾃旋量⼦化坐标轴, as long as 只要 spin-orbit coupling is not included. Spin-orbit coupling,however, couples ⼀对、⼀双 the spin to the crystal structure. Spin orbit coupling is switched on 开启 by selectingLSORBIT = .TRUE.
SAXIS = s_x s_y s_z (quantisation axis for spin ⾃旋量⼦化轴)
GGA_COMPAT = .FALSE. ! apply spherical 球⾯ cutoff 截断能 on gradient field 梯度场
where the default for SAXIS= (0+,0,1)(the notation 符号 0+ implies 意味着 an infinitesimal ⽆穷⼩ small positive number in x direction). The flag GGA_COMPAT (see Sec. 6.42) is optional 选项 and should be set when small energy differences in thesub 副、下标 meV regime 体制、状态 need to be calculated (often the case for magnetic anisotropy calculations 磁各向异性计算). All magnetic moments are now given with respect to 关于 the axis 坐标轴 (S x ,S y ,S z ), where we have adopted 应⽤the convention 惯例 that all magnetic moments and spinor-like quantities written or read by VASP are given with respect tothis axis .
This includes the MAGMOM line in the INCAR file, the total and local magnetizations in the OUTCAR and PROCAR file, thespinor ⾃旋量-like orbitals in the WAVECAR file, and the magnetization density in the CHGCAR file. With respect to thecartesian 笛卡尔 lattice vectors the components 组件、部分 of the magnetization are (internally 内部地、内在的) given byaxis z axis x z axis z
axis y x y axis z
axis y axis x x m m m m m m m m m m m )cos()sin()sin()sin()cos()sin()cos()cos(*)sin()sin()cos()cos(ββαβααβαβααβ+-=++=+-=
Where m axis is the externally 外部地 visible 可得到的，现有的，可见的 magnetic moment. Here, α is the angle between theSAXIS vector (s x , s y , s z ) and the cartesian vector x
, and β is the angle between the vector SAXIS and the cartesian vector z ?: zy x x y
s s s a s s a ||tan ,tan 22+==βα The inverse 倒转、翻转 transformation 转化、转换 is given byz y x axis y x axis z y x axis m m m m m m m m m m m z yx
)cos()sin()sin()cos()sin()cos()sin()sin()sin()cos()cos()cos(βαβαβααβαβαβ++=+-=++=
It is easy to see that for the default (s x , s y , s z ) = (0+,0,1), both angles are zero, i.e. β=0 and α=0. In this case, the internalrepresentation is simply equivalent to the external representation: axis z
z axis y y axis x x m m m m m m ===,, The second important case, is 0=axis x m and 0=axis ym . In this case222222
/)(cos /)cos(*)sin(z y x z axis z axis x z y z
y z axis z axis z x s s s s m m m m s s s s m m m x ++===++==βαβ
Hence 因此、今后 now the magnetic moment is parallel to the vector SAXIS. Thus there are two ways to rotate the spins inan arbitrary 任意的 direction, either by changing the initial magnetic moments MAGMOM or by changing SAXIS.
To initialise calculations with the magnetic moment parallel to a chosen vector (x,y,z), it is therefore 因此 possible to eitherspecify 指定 (assuming 假定、假设 a single atom in the cell)MAGMOM = x y z ! local magnetic moment in x,y,zSAXIS = 0 0 1 ! quantisation axis parallel to zor
MAGMOM = 0 0 total_magnetic_moment ! local magnetic moment parallel to SAXISSAXIS = x y z ! quantisation axis parallel to vector (x,y,z)
Both setups should in principle yield exactly the same energy, but for implementation 实现 reasons the second method isusually more precise 精确. The second method also allows to read a preexisting WAVECAR file (from a collinear or noncollinear run), and to continue the calculation with a different spin orientation. When a non collinear WAVECAR file is read,the spin is
assumed 假定 to be parallel to SAXIS (hence 因此 VASP will initially report a magnetic moment in the z-direction only).The recommended 被推荐的 procedure 过程、步骤 for the calculation of magnetic anisotropies is therefore 因⽽、表⽰结果(please check the section on LMAXMIX 6.63):
Start with a collinear calculation and calculate a W A VECAR and CHGCAR file. ? Add the tagsLSORBIT = .TRUE.
ICHARG = 11 ! non selfconsistent run, read CHGCAR
LMAXMIX = 4 ! for d elements increase LMAXMIX to 4, f: LMAXMIX = 6! you need to set LMAXMIX already in the collinear calculationSAXIS = x y z ! direction of the magnetic fieldNBANDS = 2 * number of bands of collinear run
GGA_COMPAT = .FALSE. ! apply spherical cutoff on gradient field
V ASP reads in the W A VECAR and CHGCAR files, aligns 排列 the spin quantization axis parallel to SAXIS, which implies意味着 that the magnetic field is now parallel to SAXIS, and performs a non selfconsistent calculation. By comparing theenergies for different orientations the magnetic anisotropy can be determined 确定. Please mind, that a completely
selfconsistent calculation (ICHARG=1) is in principle ⼤体上、原则上 also possible with V ASP, but this would allow the thespinor wavefunctions to rotate from their initial orientation parallel to SAXIS until the correct groundstate is obtained, i.e. untilthe magnetic moment is parallel to the easy axis （?=the easy magnetic axis ）. In practice this rotation will be slow, sincereorientation 再定位 of the spin gains 获得 little energy. Therefore if the convergence 收敛 criterion 标准 is not too tight,
sensible 明智的 results might be obtained even for fully selfconsistent calculations (in the few cases we have tried 可靠地，试验过的 selfconsistentcy worked without problems).
Be very careful with symmetry. We recommend 建议 to switch off 关掉 symmetry (ISYM=0) altogether 完全地, when spin orbitcoupling is selected. Often the k-point set changes from one to the other spin orientation, worsening 恶化 the transferability ofthe results (also the W A VECAR file can not be reread properly 正确地 if the number of k-points changes). The flag
GGA_COMPA T is usually required and should be set, since magnetic anisotropy energies are often in the sub meV regime(see Sec. 6.42).
Generally be extremely ⾮常 careful, when using spin orbit coupling and, specifically 特别地, magnetic anisotropies: energydifferences are tiny 微⼩的, k-point convergence 收敛 is tedious 冗长乏味 and slow, and the computer time might be huge.Additionally此外, this feature这⼀特征-- although long implemented应⽤in V ASP-- is still in a late beta stage, as you mightdeduce from推断，从...得出结论the frequent频繁的updates升级、更新. No promise允诺, that your results will be useful! Hereis a small summary总结from the README file:
20.11.2003: The present提出GGA routine程序breaks the symmetry slightly轻微地for non orthorhombic正交晶系cells. A
spherical球⾯的cutoff is now imposed on应⽤于the gradients and all intermediate中间的results in reciprocal互逆space. Thischanges the GGA results slightly (usually by 0.1 meV per atom), but is important for magnetic anisotropies.
05.12.2003: continue... Now V ASP.4.6 defaults to the old behavior GGA_COMPA T=.TRUE., the new behavior can beobtained by setting GGA_COMPA T=.FALSE. in the INCAR file.
12.08.2003: MAJOR主要的BUG故障FIX固定in symmetry.F and paw.F: for non-collinear calculations the symmetry routines惯例did not work properly正确地
If you have read the previous lines, you will realize that it is recommended推荐to set GGA_COMPA T=.FALSE. for noncollinear calculations in V ASP.4.6 and V ASP.5.2, since this improves the numerical precision of GGA calculations.degree:
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Error EDDDA V: Call to ZHEGV failed. Returncode = 13 1 8
The earlier solution suggested by admin（DOS操作系统中，超级管理员。⾏政、管理）(suppressing制⽌的the line #defineUSE_ZHEEVX in davidson.F, subrot.F, and wavpre_noio.F and recompiling V ASP) does not work, i.e. the same errormessages, and the same indication迹象、表⽰of ZHEGV failure, still appear出现. I may add now that the problem appearsboth with the lapack which comes with V ASP and with a system-native lapack library. The warnings given suggest that theproblem actually appears at an earlier stage阶段, in which a matrix is generated with inadequate不适当的values which makeit nonhermitian, and consequently ZHEGV fails even if working correctly; the solution thus would not be to avoid usingZHEGV, but to avoid an incorrect generation of the said matrix. Can someone give an idea to really solve the problem?答：Please try if it works by adding \"LSCALAPACK = .FALSE.\" in your INCAR.对策：grep LSCALAPACK OUTCAR 空设置：LSCALAPACK = .FALSE
问：No; adding \"LSCALAPACK = .FALSE.\" in INCAR makes no dfference, the problem continues the same.问：I was successful to fix this problem解决此问题by using IALGO=48 instead of IALGO=Default。unfortunately, when i set IALGO=48, the new warning is：WARNING in EDDRMM: call to ZHEGV failed, returncode = 6 3 14how to solve this problem? what does \"ZBRENT\" mean?对策：grep IALGO OUTCAR
IALGO = 68 algorithm （INCAR ALGO=Fast）设置：IALGO=48
please try one of the following:
1) choose a different algorithm for ionic optimization (IBRION=1) 采⽤准⽜顿算法来优化原⼦位置2) set ADDGRID=.True. in INCAR (only for vasp releases发布管理、释放、豁免4.4.5 and newer)对策：grep ADDGRID OUTCAR 空grep IBRION OUTCAR
IBRION = 2 ionic relax: 0-MD 1-quasi-New 2-CG设置ADDGRID=.True. In INCAR设置IBRION=1 in INCAR错误：
internal ERROR RSPHER:running out of buffer 0 013 1 0
nonlr.F:Out of buffer RSPHER得到的CONTCAR是空的！结构优化出现错误：
Internal内部的、内在的ERROR RSPHER:running out of buffer缓冲0 013 1 0
nonlr.F:Out of buffer RSPHER
解决：将NPAR=1修改成4（或者2），问题得以解决。
分两步（scf⾮磁线性计算，bands读取CHGCAR、WAVECAR做⾮线性⾃旋轨道耦合计算），能带计算出错：ERROR:while reading WAVECAR, plane wave coefficients系数changed 57286 28837
Solution: You have to continue with the converged收敛CHGCAR, because most probably, you will increase增加/change改变the k-mesh to get a denser密集的、浓厚的k-grid to calculate the DOS accurately. Then, WAVECAR will not be read correctlybecause the wavefunction-coefficients波函数-系数are stored存储k-point wise明智的concerning涉及the READ error ofCHGCAR: please check whether the FFT meshes have changed. please make sure that1) the CHGCAR really is in the working directory⽬录at runtime运⾏时间2) the fft meshes of CHGCAR are compatible兼容的
The main points is in this sentence \"plane wave coefficients changed \
process is different, therefore, the plane wave coefficients changed in these two process is not identical完全相同的. You canfind the values of NGXF, NGYF and NGZF in the CHGCAR or OUTCAR of the scf, and then add these three parameters inthe INCAR of the nonscf. OK, the problem is resolved.
在静态计算的CHGCAR或者OUTCAR中找到NGXF, NGYF和NGZF，将这些参数加到⾮静态计算的INCAR中：grep NGXFOUTCAR
dimension x,y,z NGXF= 64 NGYF= 64 NGZF= 840support grid NGXF= 64 NGYF= 64 NGZF= 840
NGXF,Y,Z is equivalent to a cutoff of 25.43, 25.43, 25.05 a.u.对策：在能带计算INCAR中加⼊NGXF= 64 NGYF= 64 NGZF= 840修改之后，bands中出现错误：
ERROR: non collinear calculations require that VASP is compiled without the flag -DNGXhalf and -DNGZhalf解决：待解决!⽹上经验：
non collinear calculations require that V ASP is compiled without the flag -DNGXhalf and -DNGZhalf.⼀、请加⼊SOC1）INCAR中加⼊LNONCOLLINEAR=.True.LSORBIT=.True.LORBMOM=.True.
ISYM= -1 （？不对，ISYM取值0,1,2,3）
【SAXIS =⾃旋轴⽅向；MAGMOM= 每个原⼦的初始磁矩值】2) 不要忘记
to include SOC, please
1) add the following lines to INCARLNONCOLLINEAR=.True.LSORBIT=.True.
SAXIS = # please give the spin quantization axis here, like 0 0 1 for the z-axis)
MAGMOM= # please give a triplet of numbers for each atom here, and please have a look at the manual (chapter non-collinear calculations and spin-orbit tag) on how the direction of the magnetic moments has to be defined with respect to thespin-quantization axis)LORBMOM=.True.ISYM= -1
2）不要忘记如果你⽤的vasp不包含任何预编译程序命令-DNGXhalf, -DNGZhalf, -DwNGXhalf, -DwNGZhalf ，你必须重新编译vasp，因为这些参数通常对于⾮线性磁性计算是必要的，在DOSCAR中的第⼆块数据包含了E和4列s,p,d，如下：rho, m_x,m_y, m_z ，
2) don't forget that you may have to re-compile vasp without any of the precompiler (CPP) flags set: -DNGXhalf, -DNGZhalf, -DwNGXhalf, -DwNGZhalf , as necessary for non-collinear runs in general for non-collinear magnetism, the second block ofdata in DOSCAR contains E, and 4 columns for each, s,p,d, giving:rho, m_x, m_y, m_z
with m....magnetisation，it makes absolutely NO SENSE to set ISPIN=2 (up and down) for non-clollinear runs, therfore thistag is ignored when it s read from INCAR.Symbol Description
Γ Center of the Brillouin zoneSimple cubeM Center of an edgeR Corner pointX Center of a faceFace-centered cubic
K Middle of an edge joining two hexagonal facesL Center of a hexagonal face
U Middle of an edge joining a hexagonal and a square faceW Corner point
X Center of a square faceBody-centered cubic
H Corner point joining four edgesN Center of a face
P Corner point joining three edgesHexagonal
A Center of a hexagonal faceH Corner point
K Middle of an edge joining two rectangular faces
L Middle of an edge joining a hexagonal and a rectangular faceM Center of a rectangular face
1) it does not look to me as if the magnetic convergence is particularly bad. (please dont compare the moments stemmingfrom
the augmentation to the total moments).
have you decreased AMIX,BMIX, AMIX_MAG and BMIX_MAG for this run?
2)the mixing parameters must not have any influence on the converged total energies.3) if your system has a magnetic moment, you have to set ISPIN.
unless you set LNONCOLLINEAR explicitely , collinear magnetism is assumed by default, there is nothing to be specified in
extra (except from starting with FM or AFM configuration by choosing the MAGMOMs accordingly)
4) please in any case check if the convergence of ALL ionic steps is bad. (consider that it may be possible that you relaxedinto an unreasonable geometry which does not converge electronically).without knowing further details, I would recommend to try the following:
please keep the low mixing parameters check if the k-mesh is converged try if a different BZ-integration (ISMEAR=1) andslightly larger smearing (SIGMA) helps set LMAXMIX=6 if your system contains d-elementsISYM-tag and SYMPREC-tagISYM = 0|1|2|3Default 1
switch symmetry on (1, 2 or 3) or off (0).
For ISYM=2 a more efficient, memory conserving symmetrisation of the charge density is used. This reduces memoryrequirements in particular for the parallel version. ISYM=2 is the default if PAW data sets are used.ISYM=1 is the default if VASP runs with US-PP’s.
For ISYM=3, the forces and the stress tensor only are symmetrized, whereas the charge density is left unsymmetrized(VASP.5.1 only).
This option might be useful in special cases, where charge/orbital ordering lowers the crystal symmetry, and the user wantsto conserve 【保存, 保藏】the symmetry of the positions during relaxation.
However, the flag must be used with great caution, since a lower symmetry due to charge/orbital ordering, in principle alsorequires to sample the Brillouin zone using
a k-point mesh compatible with the lower symmetry caused by charge/orbital ordering.
The program determines automatically the point group symmetry and the space group according to the POSCAR file and theline MAGMOM in the INCAR file.
The SYMPREC-tag (VASP.4.4.4 and newer versions only) determines how accurate the positions in the POSCAR file mustbe. The default is 10?5, which is usually suffiently large even if the POSCAR file has been generated with a single precisionprogram.
Increasing the SYMPREC tag means, that the positions in the POSCAR file can be less accurate.During the symmetry analysis, VASP determines the Bravais lattice type of the supercell,
the point group symmetry and the space group of the supercell wit h basis (static and dynamic) - and prints the namesof the group (space group: only ’family’),
the type of the generating elementary (primitive) cell if the supercell is a non-primitive cell,
all ’trivial non-trivial’ translations (= trivial translatio ns of the generating elementary cell within the supercell) —needed forsymmetrisation of the charge,
the symmetry-irreducible set of k-points if automatic k-mesh generation was used
and additionally the symmetry irreducible set of tetrahedra if the tetrahedron method was chosen together with the automatick-mesh generation and of course also the corresponding weights (’symmetry degeneracy’),
and tables marking and connecting symmetry equivalent ions.The symmetry analyses is done in four steps: First the point group symmetry of the lattice (as supplied by the user) is determined.
Then tests are performed, whether the basis breaks symmetry. Accordingly these symmetry operations are removed. The initial velocities are checked for symmetry breaking.
Finally, it is checked wheter MAGMOM breaks the symmetry. Correspondingly themagnetic symmetry group is determined(VASP.4.4.4 and newer releases only; if you use older version please also see section 6.12). The program symmetrisesautomatically:
The t otal charge density according to the determined space group The forces on the ions according to the determined space group. The stress tensor according to the determined space group
Why is symmetrisation necessary: Within LDA the symmetry of the supercell and the charge density are always the same.This symmetry is broken, because a symmetry-irreducible set of k-points is used for the calculation.To restore the correct charge density and the correct forces it is necessary to symmetrise these quantities.
It must be stressed that VASP does not determine the symmetry elements of the primitive cell. If the supercell has a lowersymmetry than the primitive cell only the lower symmetry of the supercell is used in the calculation. In this case one shouldnot expect that forces that should be zero according to symmetry will be precisely zero in actual calculations.The symmetry of the primitive cell is in fact broken in several places in VASP: local potential:
In reciprocal space, the potential V(G) should be zero, if G is not a reciprocal lattice vector of the primitive cell.
For PREC=Med, this is not guaranteed due to ”aliasing” or wrap around and the charge density (and therefore the Hatreepotential) might violate this point. But even for PREC=High, small errors are introduced, because the exchange correlationpotential Vxc is calculated in real space. k-points:
In most cases, the automatic k-point grid does not have the symmetry of the primitive cell.错误：
internal ERROR: DEPLE: IRDMAX must be increased to 0internal ERROR: DEPLE: IRDMAX must be increased to 0错误：
ERROR FEXCF: supplied exchange-correlation table is too small, maximal index : 9344428计算soc能带时，选择ISTART=1，即读⼊静态计算得到的W A VECAR能带计算出错：
ERROR: while reading W A VECAR, plane wave coefficients changed 16135
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