前面我已经通过将一个紧束缚模型转换成WannierTools可计算的数据,研究了一下模型的拓扑性质,这里我想通过计算一下Bi$_2$Se$_3$这个材料的一些具体性质,因为这个材料是可以通过VASP计算得到其对应的能带及其它一些信息的,所以我可以结合VASP来完全重复这个材料具体信息,而且这个例子也是学习第一性计算较好的算例,所以就在这里仔细学习并记录一下.
wt.in文件内容解析
&TB_FILE
Hrfile = 'wannier90_hr.dat'
Package = 'VASP' ! obtained from VASP, it could be 'VASP', 'QE', 'Wien2k', 'OpenMx'
/
LATTICE
Angstrom
-2.069 -3.583614 0.000000 ! crystal lattice information
2.069 -3.583614 0.000000
0.000 2.389075 9.546667
ATOM_POSITIONS
5 ! number of atoms for projectors
Direct ! Direct or Cartisen coordinate
Bi 0.3990 0.3990 0.6970
Bi 0.6010 0.6010 0.3030
Se 0.0000 0.0000 0.5000
Se 0.2060 0.2060 0.1180
Se 0.7940 0.7940 0.8820
PROJECTORS
3 3 3 3 3 ! number of projectors
Bi px py pz ! projectors
Bi px py pz
Se px py pz
Se px py pz
Se px py pz
SURFACE ! Specify surface with two vectors, see doc
1 0 0
0 1 0
!> bulk band structure calculation flag
&CONTROL
BulkBand_calc = T
BulkBand_points_calc = T
DOS_calc = T
SlabBand_calc = T
SlabBandWaveFunc_calc = T
SlabBand_plane_calc = T
WireBand_calc = T
SlabSS_calc = T
SlabArc_calc = T
SlabQPI_calc = T
Z2_3D_calc = T
SlabSpintexture_calc = T
Wanniercenter_calc = T
/
&SYSTEM
NSLAB = 4 ! for thin film system
NSLAB1= 2 ! nanowire system
NSLAB2= 2 ! nanowire system
NumOccupied = 18 ! NumOccupied
SOC = 1 ! soc
E_FERMI = 4.4195 ! e-fermi, a global shift of the energy levels
surf_onsite= 0.0 ! surf_onsite
/
&PARAMETERS
Eta_Arc = 0.001 ! infinite small value, like brodening
E_arc = 0.0 ! energy level for contour plot of spectrum
OmegaNum = 400 ! omega number
OmegaMin = -0.6 ! energy interval
OmegaMax = 0.5 ! energy interval
Nk1 = 10 ! number k points odd number would be better
Nk2 = 10 ! number k points odd number would be better
Nk3 = 10 ! number k points odd number would be better
NP = 1 ! number of principle layers
Gap_threshold = 0.01 ! threshold for FindNodes_calc output
/
KPATH_BULK ! k point path
4 ! number of k line only for bulk band
G 0.00000 0.00000 0.0000 Z 0.00000 0.00000 0.5000
Z 0.00000 0.00000 0.5000 F 0.50000 0.50000 0.0000
F 0.50000 0.50000 0.0000 G 0.00000 0.00000 0.0000
G 0.00000 0.00000 0.0000 L 0.50000 0.00000 0.0000
KPATH_SLAB
2 ! numker of k line for 2D case
K 0.33 0.67 G 0.0 0.0 ! k path for 2D case
G 0.0 0.0 M 0.5 0.5
KPLANE_SLAB
-0.1 -0.1 ! Original point for 2D k plane
0.2 0.0 ! The first vector to define 2D k plane
0.0 0.2 ! The second vector to define 2D k plane for arc plots
KPLANE_BULK
0.00 0.00 0.50 ! Original point for 3D k plane
1.00 0.00 0.00 ! The first vector to define 3d k space plane
0.00 0.50 0.00 ! The second vector to define 3d k space plane
KCUBE_BULK
-0.50 -0.50 -0.50 ! Original point for 3D k plane
1.00 0.00 0.00 ! The first vector to define 3d k space plane
0.00 1.00 0.00 ! The second vector to define 3d k space plane
0.00 0.00 1.00 ! The third vector to define 3d k cube
WANNIER_CENTRES ! copy from wannier90.wout
Cartesian
-0.000040 -1.194745 6.638646
0.000038 -1.196699 6.640059
-0.000032 -1.192363 6.640243
-0.000086 -3.583414 2.908040
0.000047 -3.581457 2.906587
-0.000033 -3.585864 2.906443
-0.000001 1.194527 4.773338
0.000003 1.194538 4.773336
-0.000037 1.194536 4.773327
0.000006 -1.194384 1.130261
-0.000018 -1.216986 1.140267
0.000007 -1.172216 1.140684
0.000011 -3.583770 8.416406
-0.000002 -3.561169 8.406398
-0.000007 -3.605960 8.405979
0.000086 -1.194737 6.638626
-0.000047 -1.196693 6.640080
0.000033 -1.192286 6.640223
0.000040 -3.583406 2.908021
-0.000038 -3.581452 2.906608
0.000032 -3.585788 2.906424
0.000001 1.194548 4.773330
-0.000003 1.194537 4.773332
0.000037 1.194539 4.773340
-0.000011 -1.194381 1.130260
0.000002 -1.216981 1.140268
0.000007 -1.172191 1.140687
-0.000006 -3.583766 8.416405
0.000018 -3.561165 8.406400
-0.000007 -3.605935 8.405982
设置紧束缚哈密顿量
&TB_FILE ! 输入控制文件中共有4个这样的名字 TB_FILE, SYSTEM, CONTROL, PARAMETERS,分别用来控制不同内容
Hrfile = 'wannier90_hr.dat' ! 紧束缚哈密顿量的位置
Package = 'VASP' ! obtained from VASP, it could be 'VASP', 'QE', 'Wien2k', 'OpenMx'
/
设置体系的一些性质
&SYSTEM
Nslab = 10 !Number of slabs for slab band, The default value is 10
Nslab1= 6 ! The thickness of nano ribbon
Nslab2= 6
NumOccupied = 18 ! 占据的Wannier能带的数目,这个设置一定要正确才行
SOC = 1 ! SOC>0代表模型中考虑自旋轨道耦合,SOC=0则代表不考虑自旋轨道耦合
E_FERMI = 4.4195 ! real-valued, Fermi level for the given tight binding model
Bx= 0, By= 0, Bz= 0 ! Bx By Bz
surf_onsite= 0.0 ! real-valued, Additional onsite energy on the surface, you can set this to see how surface state changes
/
计算控制
BulkBand_calc = T ! 计算体态能带
BulkFS_calc = F ! 体系费米面计算
BulkGap_cube_calc = F ! Energy gap for a given k cube for bulk system
BulkGap_plane_calc = F ! Energy gap for a given k plane for bulk system
SlabBand_calc = T ! Band structure for 2D slab system(开边界能带计算)
WireBand_calc = F ! Band structure for 1D ribbon system(若为3D体系,则表示开两个方向边界进行计算)
SlabSS_calc = T ! Surface spectrum A(k,E) along a kline and energy interval for slab system(计算开边界时候的表面态)
SlabArc_calc = F ! Surface spectrum A(k,E0) for fixed energy E0 in 2D k-plane for slab system (计算确定能量下的表面态)
SlabSpintexture_calc = T ! Spin texture in 2D k-plane for slab system(开边界表面态上的自旋分布计算)
wanniercenter_calc = F ! 计算Wannier Center的变化
BerryCurvature_calc = F ! 计算体系Berry曲率
/
参数设置
E_arc = 0.0 ! 计算费米弧时候的能量
Eta_Arc = 0.001 ! infinite small value, like broadening(格林函数的小虚部)
OmegaNum = 200 ! omega number
OmegaMin = -0.6 ! energy interval
OmegaMax = 0.5 ! energy interval
Nk1 = 50 ! number k points
Nk2 = 50 ! number k points
Nk3 = 50 ! number k points
NP = 2 ! You need to do a convergence test by setting Np= 1, Np=2, Np=3, and check the surface state spectrum.
! Basically, the value of Np depends on the spread of Wannier functions you constructed. One thing should
! be mentioned is that the computational time grows cubically of Np.
Gap_threshold = 1.0 !This value is used when you do energy gap calculation like BulkGap_cube_calc=T
/
晶体结构信息设置
LATTICE
Angstrom ! 长度单位
-2.069 -3.583614 0.000000 ! 元胞基矢
2.069 -3.583614 0.000000
0.000 2.389075 9.546667
原子位置
ATOM_POSITIONS
5 ! 元胞内有5个原子
Direct ! 原子位置的表示方式
Bi 0.3990 0.3990 0.6970 ! 每个原子的位置坐标
Bi 0.6010 0.6010 0.3030
Se 0 0 0.5
Se 0.2060 0.2060 0.1180
Se 0.7940 0.7940 0.8820
轨道投影
PROJECTORS
3 3 3 3 3 ! 每个原子的投影轨道数目
Bi pz px py ! 设置每个原子的投影轨道
Bi pz px py
Se pz px py
Se pz px py
Se pz px py
表面计算设置
SURFACE ! 设置要研究的是哪个面上的性质
1 0 0 ! a11, a12, a13
0 1 0 ! a21 a22 a23
体态能带计算
KPATH_BULK ! 计算体态能带时,动量空间中路径的选择
4 ! number of k line only for bulk band
G 0.00000 0.00000 0.0000 Z 0.00000 0.00000 0.5000
Z 0.00000 0.00000 0.5000 F 0.50000 0.50000 0.0000
F 0.50000 0.50000 0.0000 G 0.00000 0.00000 0.0000
G 0.00000 0.00000 0.0000 L 0.50000 0.00000 0.0000
特殊点能带计算
KPOINTS_3D !You can calculate the properties on some kpoints you specified in point mode
4 ! number of k points
Direct ! Direct or Cartesian
0.00000 0.00000 0.0000
0.00000 0.00000 0.5000
0.50000 0.50000 0.0000
0.00000 0.00000 0.0000
slab结构计算表面态
KPATH_SLAB ! 计算表面态时候的路径选择
2 ! numker of k line for 2D case
K 0.33 0.67 G 0.0 0.0 ! k path for 2D case
G 0.0 0.0 M 0.5 0.5
2D平面上arc计算
KPLANE_SLAB
-0.1 -0.1 ! Original point for 2D k plane
0.2 0.0 ! The first vector to define 2D k plane
0.0 0.2 ! The second vector to define 2D k plane for arc plots
3D体BZ中的计算
KPLANE_BULK
-0.50 -0.50 0.00 ! Original point for 3D k plane
1.00 0.00 0.00 ! The first vector to define 3d k space plane
0.00 1.00 0.00 ! The second vector to define 3d k space plane
KCUBE_BULK
KCUBE_BULK
-0.50 -0.50 -0.50 ! Original point for 3D k plane
1.00 0.00 0.00 ! The first vector to define 3d k space plane
0.00 1.00 0.00 ! The second vector to define 3d k space plane
0.00 0.00 1.00 ! The third vector to define 3d k cube
Wannier Center计算
WANNIER_CENTRES ! copy from wannier90.wout(需要结合Wannier90来产生数据)
Cartesian
-0.000040 -1.194745 6.638646
0.000038 -1.196699 6.640059
-0.000032 -1.192363 6.640243
-0.000086 -3.583414 2.908040
0.000047 -3.581457 2.906587
-0.000033 -3.585864 2.906443
-0.000001 1.194527 4.773338
0.000003 1.194538 4.773336
-0.000037 1.194536 4.773327
0.000006 -1.194384 1.130261
-0.000018 -1.216986 1.140267
0.000007 -1.172216 1.140684
0.000011 -3.583770 8.416406
-0.000002 -3.561169 8.406398
-0.000007 -3.605960 8.405979
0.000086 -1.194737 6.638626
-0.000047 -1.196693 6.640080
0.000033 -1.192286 6.640223
0.000040 -3.583406 2.908021
-0.000038 -3.581452 2.906608
0.000032 -3.585788 2.906424
0.000001 1.194548 4.773330
-0.000003 1.194537 4.773332
0.000037 1.194539 4.773340
-0.000011 -1.194381 1.130260
0.000002 -1.216981 1.140268
0.000007 -1.172191 1.140687
-0.000006 -3.583766 8.416405
0.000018 -3.561165 8.406400
-0.000007 -3.605935 8.405982
结果
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