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 DAV 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+01 RMM: 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+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 DAV 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） 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 (5 steps 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+03 0.98155E+02 -0.87140E+01 48832 0.949E+01BRMIX: very serious problems the old and the new charge density differ old charge density: 252.00012 new 252.29979 0.809E+01 WARNING: Sub-Space-Matrix is not hermitian in DAV 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 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 = 0.4000 and BMIX = 1.0000

设置： 初始值 AMIX =0.0100； BMIX =0.0001 AMIX = 0.1000； BMIX = 0.0010 AMIX =0.20; BMIX = 0.01 AMIX=0.2、BMIX=0.001 AMIX=0.3、BMIX=0.1 AMIX=0.4 收敛值 AMIX = 0.01; BMIX = 0.00 AMIX = 0.10; BMIX = 0.00 AMIX =0.20; BMIX = 0.01 AMIX=0.2、BMIX=0.001 AMIX=0.3、BMIX=0.1 AMIX = 0.40; BMIX = 1.00 结果 计算无误 计算无误 计算无误 计算无误 计算无误 静态log: WARNING in EDDRMM: call to ZHEGV failed, returncode = 6 3 **,能带一样 AMIX=0.02 AMIX=0.1 AMIX = 0.02; BMIX = 1.00 AMIX = 0.10; BMIX = 1.00 计算无误 静态log: WARNING in EDDRMM: call to ZHEGV failed, returncode = 6 3 **,能带一样 AMIX=0.3 AMIX = 0.30; BMIX = 1.00 静态log: WARNING in EDDRMM: call to ZHEGV 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 'VASP/VAMP' (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 space optimization 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 VASP is compiled without the flag -DNGXhalf and -DNGZhalf

分析：VASP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VASP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VASP4.5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。VASP有能力读入之前非磁或非线性计算得到的WAVECAR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WAVECAR和CHGCAR文件。 第二步，读入WAVECAR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_COMPAT = .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_COMPAT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VASP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，WAVECAR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： axisaxismx?cos(?)cos(?)mx?sin(?)my?sin(?)*cos(?)mzaxisaxismy?cos(?)sin(?)mx?cos(?)my?sin(?)sin(?)mzaxis 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axismz??sin(?)mx?cos(?)mzaxis??atan卡尔坐标z轴的夹角,sysx,??atan22|sx?sy|sz, 以下等式得到逆变化： maxis?cos(?)cos(?)mx?cos(?)sin(?)my?sin(?)mzxmaxis??sin(?)mx?cos(?)myymaxis?sin(?)cos(?)mx?sin(?)sin(?)my?cos(?)mzz 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：axisaxisaxismx?mx,my?my,mz?mz，第二种重要的情况，是axismx?0和axismy?0，在这种情况下： 22mx?sin(?)*cos(?)mzaxis?mzaxissz/s2x?sy?szmy?axis22mz?cos(?)mx?mzaxissz/sx?sy?sz2

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 y z !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SAXIS SAXIS = 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WAVECAR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WAVECAR文件，自旋假定平行于SAXIS（因此VASP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WAVECAR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LMAXMIX SAXIS = x y z ! 磁场的方向 NBANDS = 2 * 线性计算能带数 GGA_COMPAT = .FALSE. ! 在梯度场中应用球面截断能 VASP读入WAVECAR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VASP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WAVECAR将不会被正确地重新读取）。GGA_COMPAT 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VASP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VASP.4.6默认旧的行为GGA_COMPAT=.TRUE.，新的行为将可以通过在INACR中设置GGA_COMPAT=.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VASP.4.6和VASP.5.2版本中进行非线性计算推荐设置GGA_COMPAT=.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-orbit coupling 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-tag Supported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 WAVECAR and CHGCAR file. Second, read the WAVECAR 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 three entries correspond to the initial local magnetic moment for each ion in x, y and z direction respectively. The line MAGMOM = 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 but no 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 define the 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 selecting LSORBIT = .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 ? direction). The flag GGA_COMPAT (see Sec. 6.42) is optional选项 and should be set when small energy differences in the xsub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 (Sx,Sy,Sz), 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 to this axis. This includes the MAGMOM line in the INCAR file, the total and local magnetizations in the OUTCAR and PROCAR file, the spinor自旋量-like orbitals in the WAVECAR file, and the magnetization density in the CHGCAR file. With respect to the cartesian笛卡尔 lattice vectors the components组件、部分 of the magnetization are (internally内部地、内在的) given by axisaxismx?cos(?)cos(?)mx?sin(?)my?sin(?)*cos(?)mzaxisaxismy?cos(?)sin(?)mx?cos(?)my?sin(?)sin(?)mzaxisaxismz??sin(?)mx?cos(?)mzaxis Where maxis 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 the SAXIS vector (sx, sy, sz) and the cartesian vector ?, and β is the angle between the vector SAXIS and the cartesian vector z?: x??atansysx,??atan22|sx?sy| szThe inverse倒转、翻转 transformation转化、转换 is given by maxis?cos(?)cos(?)mx?cos(?)sin(?)my?sin(?)mzxmaxis??sin(?)mx?cos(?)myymaxis?sin(?)cos(?)mx?sin(?)sin(?)my?cos(?)mzz It is easy to see that for the default (sx, sy, sz) = (0+,0,1), both angles are zero, i.e. β=0 and α=0. In this case, the internal representation is simply equivalent to the external representation: m?maxis,m?maxis,m?maxis xxyyzzaxisaxisThe second important case, is mx?0and my?0. In this case

22mx?sin(?)*cos(?)mzaxis?mzaxissz/s2x?sy?szmy?axis22mz?cos(?)mx?mzaxissz/sx?sy?sz2 Hence因此、今后 now the magnetic moment is parallel to the vector SAXIS. Thus there are two ways to rotate the spins in an 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 either specify指定 (assuming假定、假设 a single atom in the cell) MAGMOM = x y z ! local magnetic moment in x,y,z SAXIS = 0 0 1 ! quantisation axis parallel to z or MAGMOM = 0 0 total_magnetic_moment ! local magnetic moment parallel to SAXIS SAXIS = 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 is usually more precise精确. The second method also allows to read a preexisting WAVECAR file (from a collinear or non collinear 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 WAVECAR and CHGCAR file. Add the tags LSORBIT = .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 calculation SAXIS = x y z ! direction of the magnetic field NBANDS = 2 * number of bands of collinear run GGA_COMPAT = .FALSE. ! apply spherical cutoff on gradient field VASP reads in the WAVECAR 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 the energies 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 VASP, but this would allow the the spinor wavefunctions to rotate from their initial orientation parallel to SAXIS until the correct groundstate is obtained, i.e. until the magnetic moment is parallel to the easy axis（?=the easy magnetic axis）. In practice this rotation will be slow, since reorientation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 orbit coupling is selected. Often the k-point set changes from one to the other spin orientation, worsening恶化 the transferability of the results (also the WAVECAR file can not be reread properly正确地 if the number of k-points changes). The flag GGA_COMPAT 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: energy differences 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 VASP-- is still in a late beta stage, as you might deduce 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! Here is 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. This changes the GGA results slightly (usually by 0.1 meV per atom), but is important for magnetic anisotropies. 05.12.2003: continue... Now VASP.4.6 defaults to the old behavior GGA_COMPAT=.TRUE., the new behavior can be obtained by setting GGA_COMPAT=.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_COMPAT=.FALSE. for non collinear calculations in VASP.4.6 and VASP.5.2, since this improves the numerical precision of GGA calculations. degree: BSc：Bachelor of Science理科学士 MD MS：master硕士 PhD： Doctor of Philosophy 博士学位 AA Associate degree of Arts大 专 文 科 学 位 AAS Associate degree of Arts and Science大 专 文 理 科 学 位 AS Associate degree of Science大 专 理 科 学 位 BA Bachelor of Arts 文 科 本 科 学 位 BS Bachelor of Science理 科 本 科 学 位 MA Master of Arts 文 科 硕 士 MBA Master of Business Administration 商 学 硕 士 MS Master of Science理 科 硕 士 Ph.D. Doctor of Phiolosphy 哲 学(通 才)博 士 JD Doctor of Journalism 新 闻 博 士 MD Doctor of Medicine 医 学 博 士 DVM Doctor of Veterinry 兽 医 博 士 Call to ZHEGV failed Error EDDDAV: 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 #define USE_ZHEEVX in davidson.F, subrot.F, and wavpre_noio.F and recompiling VASP) does not work, i.e. the same error messages, and the same indication迹象、表示 of ZHEGV failure, still appear出现. I may add now that the problem appears both with the lapack which comes with VASP and with a system-native lapack library. The warnings given suggest that the problem actually appears at an earlier stage阶段, in which a matrix is generated with inadequate不适当的 values which make it nonhermitian, and consequently ZHEGV fails even if working correctly; the solution thus would not be to avoid using ZHEGV, 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 \对策：grep LSCALAPACK OUTCAR 空 设置： LSCALAPACK = .FALSE 问：No; adding \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 14 how to solve this problem? what does \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 0 13 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 0 13 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 correctly because the wavefunction-coefficients波函数-系数 are stored存储 k-point wise明智的 concerning涉及 the READ error of CHGCAR: please check whether the FFT meshes have changed. please make sure that 1) 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 \different, therefore, the plane wave coefficients changed in these two process is not identical完全相同的. You can find the values of NGXF, NGYF and NGZF in the CHGCAR or OUTCAR of the scf, and then add these three parameters in the 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 NGXF OUTCAR dimension x,y,z NGXF= 64 NGYF= 64 NGZF= 840 support 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 VASP is compiled without the flag -DNGXhalf and -DNGZhalf. 一、请加入SOC 1）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 INCAR LNONCOLLINEAR=.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 the spin-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 of data 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 this tag is ignored when it s read from INCAR. Symbol Description

Γ Center of the Brillouin zone Simple cube

M Center of an edge R Corner point X Center of a face Face-centered cubic

K Middle of an edge joining two hexagonal faces L Center of a hexagonal face

U Middle of an edge joining a hexagonal and a square face W Corner point X Center of a square face Body-centered cubic

H Corner point joining four edges N Center of a face

P Corner point joining three edges Hexagonal

A Center of a hexagonal face H Corner point

K Middle of an edge joining two rectangular faces

L Middle of an edge joining a hexagonal and a rectangular face M 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 stemming from 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 relaxed into 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) and slightly larger smearing (SIGMA) helps set LMAXMIX=6 if your system contains d-elements

ISYM-tag and SYMPREC-tag

ISYM = 0|1|2|3

Default 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 memory requirements 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 wants to 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 also requires 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 the line 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 must be. The default is 10?5, which is usually suffiently large even if the POSCAR file has been generated with a single precision

program.

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 with basis (static and dynamic) - and prints the names

of 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 translations of the generating elementary cell within the supercell) —needed for symmetrisation 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 automatic k-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 symmetrises automatically:

? The total 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 lower symmetry than the primitive cell only the lower symmetry of the supercell is used in the calculation. In this case one should not 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 Hatree potential) might violate this point. But even for PREC=High, small errors are introduced, because the exchange correlation potential 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 0 internal 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WAVECAR 能带计算出错： ERROR: while reading WAVECAR, plane wave coefficients changed 16135