发布时间 : 星期五 文章VASP自旋轨道耦合计算错误汇总 - 图文更新完毕开始阅读1f112a5a4531b90d6c85ec3a87c24028915f8506
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