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wannier插值能带拟合2

作者:互联网

1)  Wannier function的构造及其物理含义

2)   Wannier function的应用: GW计算能带结构绘制

Thanks to Xiegang Zhu

认识1:第一性原理计算是为了获得wannier函数,有了wannier函数后就可以不需要第一性原理,直接通过wannier函数得到电子结构,尤其是表面态信息

认识2: num_wann,num_band, Projections参数设置

认识3:画能带时高对称性k点位置的确定,可在wannier90_band.gnu文件中找到

vi wannier90_band.gnu 
set data style dots
set nokey
set xrange [0: 5.73583]
set yrange [-49.75490 :211.32533]
set arrow from  0.51430, -49.75490 to  0.51430, 211.32533 nohead
set arrow from  1.76040, -49.75490 to  1.76040, 211.32533 nohead
set arrow from  2.27470, -49.75490 to  2.27470, 211.32533 nohead
set arrow from  3.52080, -49.75490 to  3.52080, 211.32533 nohead
set arrow from  4.59941, -49.75490 to  4.59941, 211.32533 nohead
set arrow from  5.11371, -49.75490 to  5.11371, 211.32533 nohead
set xtics (" G "  0.00000," A "  0.51430," H "  1.76040," K "  2.27470," G "  3.52080," M "  4.59941," L "  5.11371," H "  5.73583)
plot "wannier90_band.dat"

#num_wann =    64  ! set to NBANDS by VASP
num_wann=8

   【nm_bands数量必须大于num_wann数量,从计算的64条能带中选取8条(num_bands),对这8条轨道采用wannier函数投影(wannier函数是实空间的函数);exclude_bands不是必须的;Nbands必须大于num_wann,否则会存在误投影情形】


num_bands=8
# for GW uncomment
exclude_bands 9-64


Begin Projections   
Si:sp3
End Projections

【 这是初始猜测轨道,必须有;对Si来说,1个硅sp3的共4条,两个硅原子8条;对于ScH3,Sc以spd计算,则一个Sc原子需1+3+5=9条轨道,一个氢原子1条轨道,所以一个分子式的ScH3需要9+3=12条轨道,一个单胞有两个分子式,则需要24条轨道,因此,

num_wann=24,

num_bands=30  !(大于24即可);

如下方式设置投影

Begin Projections

Sc:l=0;l=1;l=2
H: l=-0

End Projections】


dis_froz_max=9
dis_num_iter=1000
guiding_centres=true

网络摘录1:

http://emuch.net/html/201311/6573747.html

0.1 下载wannier90-1.2,并编译安装

在 http://www.wannier.org/download.html 下载

wannier90-1.2

修改make.sys
如果装了ifort编译器
LIBS = -lmkl_intel_lp64  -lmkl_sequential -lmkl_core
然后 make all

0.2 重新编译VASP

之后修改vasp
LIB     = -L../vasp.5.lib -ldmy  \
      ../vasp.5.lib/linpack_double.o \
      ../wannier90-1.2/libwannier.a $(SCA) (LAPACK)(LAPACK)(BLAS)
CPP    = $(CPP_) -DMPI  -DHOST=\"LinuxIFC\" -DIFC \
     -DCACHE_SIZE=4000 -DPGF90 -Davoidalloc  \
     -DMPI_BLOCK=8000 -Duse_collective -DscaLAPACK -DNGZhalf -DVASP2WANNIER90
之后重新make
分五步计算

1. step1:静态计算

INCAR
ISMEAR =  0
SIGMA  =  0.05
2.得到虚轨道(导带上方的空轨道)

INCAR
ISMEAR =  0
SIGMA  =  0.05
ALGO = Exact
NBANDS  = 64
LOPTICS=.TRUE.
NEDOS=2000

 3. GW计算

INCAR

ALGO = GW0 ; LSPECTRAL = .TRUE. ; NOMEGA = 50
NBANDS=64
LRPA = .FALSE.
LWANNIER90=.TRUE.

前三步运行vasp  【第三步运行VASP前,需写好wannier90.win参数(可先不写wannier90.win文件,试运行在第三步运行VASP,自动产生符合POSCAR和KPOINTS的wannier90.win文件,再修改该文件,运行一遍VASP),以使得运行VASP后产生 wannier90.amn, wannier90.mmn, wannier90.eig三个文件,供后续第四步的wannier90.x程序调用

 4. step4:运行 wannier90.x wannier90

wannier90.win  【第三步运行完成之后得到的参数文件】

num_wann=8     【参数含义?】
num_bands=8
# for GW uncomment
exclude_bands 9-64

Begin Projections   【开始轨道投影?】
Si:sp3
End Projections

dis_froz_max=9
dis_num_iter=1000
guiding_centres=true

begin unit_cell_cart
     2.7150000     2.7150000     0.0000000
     0.0000000     2.7150000     2.7150000
     2.7150000     0.0000000     2.7150000
end unit_cell_cart

begin atoms_cart
Si       0.0000000     0.0000000     0.0000000
Si       1.3575000     1.3575000     1.3575000
end atoms_cart

mp_grid =     4     4     4

begin kpoints
     0.0000000     0.0000000     0.0000000
     0.2500000     0.0000000     0.0000000
     0.5000000     0.0000000     0.0000000
   ........
     0.2500000    -0.5000000    -0.2500000
    -0.2500000     0.2500000    -0.5000000
end kpoints

运行 wannier90.x wannier90

 5.---step5:修改wannier90.win参数,再次运行 wannier90.x wannier90;能带即为wannier90_band.dat

num_wann=8
num_bands=8

# for GW uncomment

exclude_bands 9-64

Begin Projections
Si:sp3
End Projections

dis_froz_max=9
dis_num_iter=1000
guiding_centres=true

# Bandstructure plot
restart         =  plot
bands_plot      =  true

begin kpoint_path
L 0.50000  0.50000 0.5000 G 0.00000  0.00000 0.0000
G 0.00000  0.00000 0.0000 X 0.50000  0.00000 0.5000
X 0.50000  0.00000 0.5000 K 0.37500 -0.37500 0.0000
K 0.37500 -0.37500 0.0000 G 0.00000  0.00000 0.0000
end kpoint_path

bands_num_points 40
bands_plot_format gnuplot xmgrace

begin unit_cell_cart
     2.7150000     2.7150000     0.0000000
     0.0000000     2.7150000     2.7150000
     2.7150000     0.0000000     2.7150000
end unit_cell_cart

begin atoms_cart
Si       0.0000000     0.0000000     0.0000000
Si       1.3575000     1.3575000     1.3575000
end atoms_cart

mp_grid =     4     4     4

begin kpoints
     0.0000000     0.0000000     0.0000000
     0.2500000     0.0000000     0.0000000
     0.5000000     0.0000000     0.0000000
     0.2500000     0.2500000     0.0000000
     0.5000000     0.2500000     0.0000000
   ..........
     0.2500000    -0.5000000    -0.2500000
    -0.2500000     0.2500000    -0.5000000
end kpoints

再次运行 wannier90.x wannier90;能带即为wannier90_band.dat
如果你有gnuplot,可以直接执行wannier90_band.gnu。

标签:wannier90,num,插值,bands,wannier,0.2500000,2.7150000,0.0000000,拟合
来源: https://blog.csdn.net/bubu789/article/details/119220359