NEDOS = 2000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states关注：

1） 大部分疑问其实都来自于对物理概念的缺乏深入理解

2） GW0、GW、G0W0方法的区别

3）GW0方法计算态密度和能带结构的步骤与常规方法计算步骤的异同

http://blog.sciencenet.cn/blog-567091-675253.html

 Comments：

     前三步(DFT、virtual bands、GW0)相当于常规态密度、能带结构计算前的自洽运算，后两步为非自洽的态密度计算（LORBIT = 11）和能带结构计算（LWANNIER90_RUN = .TRUE.  ，得到wannier函数）。

脚本：

################## step 1: a DFT groundstate calculation ###################

cat > INCAR << EOF

System  = SrVO3-dft

NBANDS = 48    

ISMEAR = -5

NEDOS = 2000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states

EDIFF = 1E-8                           # high precision for groundstate calculation

#KPAR = 3
EOF

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC  > STDOUT
 
cp OUTCAR OUTCAR-01
cp STDOUT STDOUT-01

####################################### step 2: obtain DFT virtual orbitals and analysize dielectric function #####################

cat > INCAR << EOF
System  = SrVO3-get virtual orbitalss

ISMEAR = -5
NEDOS = 2000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states

ALGO = Exact  ; NELM = 1               # exact diagonalization one step suffices,NELM default
EDIFF = 1E-8                           # high precision for groundstate calculation
NBANDS = 48                            # need for a lot of bands in GW  ( how to determine the value of NBANDS?)
LOPTICS = .TRUE.                       # This is new  we need d phi/ d k  for GW calculations

#KPAR = 3

EOF

#参数说明：For ALGO=GW and ALGO=GW0 the orbitals of the previous groundstate calculations are maintained, and single shot GW calculations are performed. If NELM is set as well, several iterations are performed,  and the eigenvalues are updated in the calculation of G (ALGO=GW0)  or W and G (ALGO=GW).

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC > STDOUT

cp WAVECAR WAVECAR.LOPTICS
cp WAVEDER WAVEDER.LOPTICS
cp OUTCAR OUTCAR-02
cp STDOUT STDOUT-02

## 2-1: analysis dielectric function  ##
   
    ./plotoptics2
   
    cp  imag.dat  imag-dft2.dat
    cp  real.dat   real-dft2.dat

plotoptics2文件内容：从vasprun.xml中提取数据与绘图

 cat  plotoptics2
awk 'BEGIN{i=1} /imag/,\
               /\/imag/ \
                {a[i]=$2 ; b[i]=$3 ; i=i+1} \
    END{for (j=12;j<i-3;j++) print a[j],b[j]}' vasprun.xml > imag.dat

awk 'BEGIN{i=1} /real/,\
               /\/real/ \
                {a[i]=$2 ; b[i]=$3 ; i=i+1} \
    END{for (j=12;j<i-3;j++) print a[j],b[j]}' vasprun.xml > real.dat

cat >plotfile<<!
# set term postscript enhanced eps colour lw 2 "Helvetica" 20
# set output "optics.eps"
plot [0:25] "imag.dat" using (\$1):(\$2) w lp, "real.dat" using (\$1):(\$2) w lp
!

gnuplot -persist plotfile

# rm imag.dat real.dat plotfile

# #######################step 3:  GW0 + WANNIER90  #################################

cat > INCAR << EOF

System  = SrVO3-gw0

ISMEAR = -5
NEDOS = 2000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states

NBANDS = 48                           # need for a lot of bands in GW

ALGO = GW0                             #
NELM = 1                              # one step so this is really G0W0，not G2W0 or GW
PRECFOCK = Fast                        # select fast mode for FFT's
ENCUTGW = 100                          # energy cutoff for response function
NOMEGA = 50                          # for metal, we need a lot of frequency points;NOMEGA = 200
MAXMEM = 2500                          # memory per core
#NKRED = 2         # sample down the GW to a coarse 2x2x2 grid, for accuarate, comment out this iterm.

#KPAR = 3

EOF

cp  WAVECAR.LOPTICS WAVECAR
cp  WAVEDER.LOPTICS  WAVEDER

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC > STDOUT

cp OUTCAR OUTCAR-03
cp STDOUT STDOUTi03

# #######################step 3.1:  Analysis of the DOS   #################################

cat > INCAR << EOF

System  = SrVO3-gw0-dos

ISMEAR = -5
NEDOS = 2000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states

NBANDS = 48                           # need for a lot of bands in GW

ALGO = none                             #
NELM = 1                               # one step so this is really G0W0
PRECFOCK = Fast                        # select fast mode for FFT's
ENCUTGW = 100                          # energy cutoff for response function
NOMEGA = 200                           # metal, we need a lot of frequency points
MAXMEM = 2500                          # memory per core
#NKRED = 2                              # sample down the GW to a coarse 2x2x2 grid

#KPAR = 3
LORBIT = 11                           # for DOS

EOF

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC > STDOUT

cp OUTCAR OUTCAR-03
cp STDOUT STDOUTi-03

# giving total.dat

./plotdos  

mv  total.dat  total-dos-afterGW0.dat

 分割DOSCAR数据并通过gnuplot绘图【GW计算后会更新DOSCAR吗】

cat  plotdos
head -1006 DOSCAR | tail -1000 > total.dat
head -2007 DOSCAR | tail -1000 > Sr.dat
head -3008 DOSCAR | tail -1000 > V.dat
head -4009 DOSCAR | tail -1000 > O1.dat
head -5010 DOSCAR | tail -1000 > O2.dat
tail -1000 DOSCAR              > O3.dat

cat >plotfile<<!
plot \
"total.dat" using (\$1):(\$2) with lines title "total", \
"V.dat" using (\$1):(\$6+\$7+\$9) with lines title "V t2g", \
"V.dat" using (\$1):(\$8+\$10) with lines title "V eg"
!

gnuplot -persist plotfile

##3.2: analysis of the dielectric function ###
 
 ./plotchi
 
mv chi0.dat    chi0-real-aftergw.dat
mv chi.dat  chi-image-aftergw.dat
 
 

从OUTCAR中提取数据并绘图

 cat  plotchi
awk 'BEGIN{i=1} /HEAD OF MICRO/,\
               /XI_LOCAL/ \
                {if ($4=="dielectric") {a[i]=$1 ; b[i]=$2 ; c[i]=$3 ; i=i+1}} \
    END{for (j=1;j<i;j++) print a[j],b[j],c[j]}' OUTCAR > chi0.dat

awk 'BEGIN{i=1} /INVERSE MACRO/,\
               /XI_TO_W/ \
                {if ($4=="dielectric") {a[i]=$1 ; b[i]=$2 ; c[i]=$3 ; i=i+1}} \
    END{for (j=1;j<i;j++) print a[j],b[j],c[j]}' OUTCAR > chi.dat

cat >plotfile<<!
# set term postscript enhanced eps colour lw 2 "Helvetica" 20
# set output "optics.eps"

plot "chi0.dat" using (\$1):(\$2)  w lp lt -1 lw 2 pt 4 title "chi0 real", \
    "chi0.dat" using (\$1):(-\$3) w lp lt  0 lw 2 pt 4 title "chi0 imag", \
    "chi.dat"  using (\$1):(\$2)  w lp lt  1 lw 2 pt 2 title "chi  real", \
    "chi.dat"  using (\$1):(-\$3) w lp lt  0 lw 2 pt 2 lc 1 title "chi  imag"
!

gnuplot -persist plotfile

# rm chi0.dat chi.dat plotfile

 
# #######################step 3.1:  Analysis of gw band, by using  LWANNIER90_RUN = .TRUE.  #################################

cat > INCAR << EOF

System  = SrVO3-gw0-band

ISMEAR = -5
NEDOS = 2000  # EMIN = -20 ; EMAX = 20 uefull energy range for density of states

NBANDS = 48                            # need for a lot of bands in GW

ALGO = none                             #
NELM = 1                               # one step so this is really G0W0
PRECFOCK = Fast                        # select fast mode for FFT's
ENCUTGW = 100                          # energy cutoff for response function
NOMEGA = 200                           # metal, we need a lot of frequency points
MAXMEM = 2500                          # memory per core
#NKRED = 2                              # sample down the GW to a coarse 2x2x2 grid

#KPAR = 3
#LORBIT = 11

LWANNIER90_RUN = .TRUE.     # for band calculation，通过VASP计算得带wannier函数

EOF

cat > wannier90.win << EOF

num_wann=24

num_bands=48

# for GW uncomment
exclude_bands 31-48

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

EOF

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC  > STDOUT
 
cp OUTCAR OUTCAR-01
cp STDOUT STDOUT-01
cp  wannier90_band.dat  wannier90_band-gw.dat

完整脚本如下：

################## step 1: a DFT groundstate calculation , and get DOS and band  ###################

cat > INCAR << EOF

System  = SrVO3-dft

NBANDS = 48    

ISMEAR = -5

NEDOS = 1000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states

EDIFF = 1E-8                           # high precision for groundstate calculation

#KPAR = 3
ENCUT = 400
EOF

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC  > STDOUT
 
cp OUTCAR OUTCAR-01
cp STDOUT STDOUT-01

####################################### step 2: obtain DFT virtual orbitals and analysize dielectric function #####################

cat > INCAR << EOF
System  = SrVO3-get virtual orbitalss

ISMEAR = -5
NEDOS = 2000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states

ALGO = Exact  ; NELM = 1               # exact diagonalization one step suffices,NELM default
EDIFF = 1E-8                           # high precision for groundstate calculation
NBANDS = 48                            # need for a lot of bands in GW  ( how to determine the value of NBANDS?)
LOPTICS = .TRUE.                       # This is new  we need d phi/ d k  for GW calculations

#KPAR = 3
ENCUT = 400

EOF

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC > STDOUT

cp WAVECAR WAVECAR.LOPTICS
cp WAVEDER WAVEDER.LOPTICS
cp OUTCAR OUTCAR-02
cp STDOUT STDOUT-02

# #######################step 3:  GW0 + WANNIER90  #################################

cat > INCAR << EOF

System  = SrVO3-gw0

ISMEAR = -5
NEDOS = 2000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states

NBANDS = 48                            # need for a lot of bands in GW

ALGO = GW0                             #
NELM = 1                               # one step so this is really G0W0
PRECFOCK = Fast                        # select fast mode for FFT's
ENCUTGW = 100                          # energy cutoff for response function
NOMEGA = 200                           # metal, we need a lot of frequency points
MAXMEM = 2500                          # memory per core
#NKRED = 2         # sample down the GW to a coarse 2x2x2 grid, for accuarate, comment out this iterm.

#KPAR = 3
ENCUT = 400
EOF

cp  WAVECAR.LOPTICS WAVECAR
cp  WAVEDER.LOPTICS  WAVEDER

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC > STDOUT

cp OUTCAR OUTCAR-03
cp STDOUT STDOUTi-03

# #######################step 3.1:  Analysis of the DOS   #################################

cat > INCAR << EOF

System  = SrVO3-gw0-dos

ISMEAR = -5
NEDOS = 1000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states

NBANDS = 48                           # need for a lot of bands in GW

ALGO = none                             #
NELM = 1                               # one step so this is really G0W0
PRECFOCK = Fast                        # select fast mode for FFT's
ENCUTGW = 100                          # energy cutoff for response function
NOMEGA = 200                           # metal, we need a lot of frequency points
MAXMEM = 2500                          # memory per core
#NKRED = 2                              # sample down the GW to a coarse 2x2x2 grid

#KPAR = 3
LORBIT = 11                           # for DOS
ENCUT = 400
EOF

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC > STDOUT

cp OUTCAR OUTCAR-03
cp STDOUT STDOUTi-03

# giving total.dat

./plotdos  

mv  total.dat  total-dos-afterGW0.dat

 
# #######################step 3.1:  Analysis of gw band, by using  LWANNIER90_RUN = .TRUE.  #################################

cat > INCAR << EOF

System  = SrVO3-gw0-band

ISMEAR = -5
NEDOS = 1000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states

NBANDS = 96                            # need for a lot of bands in GW

ALGO = none                             #
NELM = 1                               # one step so this is really G0W0
PRECFOCK = Fast                        # select fast mode for FFT's
ENCUTGW = 100                          # energy cutoff for response function
NOMEGA = 50                           # metal, we need a lot of frequency points,NOMEGA = 200
MAXMEM = 2500                          # memory per core
#NKRED = 2                              # sample down the GW to a coarse 2x2x2 grid

#KPAR = 3
#LORBIT = 11

LWANNIER90_RUN = .TRUE.     # for band calculation
ENCUT = 400
EOF

cat > wannier90.win << EOF

num_wann=24

num_bands=48

# for GW uncomment
exclude_bands 31-48

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

EOF

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC  > STDOUT
 
cp OUTCAR OUTCAR-01
cp STDOUT STDOUT-01
cp  wannier90_band.dat  wannier90_band-gw.dat

完整脚本如下：

################## step 1: a DFT groundstate calculation , and get DOS and band  ###################

cat > INCAR << EOF

System  = SrVO3-dft

NBANDS = 48    

ISMEAR = -5

NEDOS = 2000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states

EDIFF = 1E-8                           # high precision for groundstate calculation

#KPAR = 3
ENCUT = 400
EOF

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC  > STDOUT
 
cp OUTCAR OUTCAR-01
cp STDOUT STDOUT-01

####################################### step 2: obtain DFT virtual orbitals and analysize dielectric function #####################

cat > INCAR << EOF
System  = SrVO3-get virtual orbitalss

ISMEAR = -5
NEDOS = 2000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states

ALGO = Exact  ; NELM = 1               # exact diagonalization one step suffices,NELM default
EDIFF = 1E-8                           # high precision for groundstate calculation
NBANDS = 48                            # need for a lot of bands in GW  ( how to determine the value of NBANDS?)
LOPTICS = .TRUE.                       # This is new  we need d phi/ d k  for GW calculations

#KPAR = 3
ENCUT = 400

EOF

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC > STDOUT

cp WAVECAR WAVECAR.LOPTICS
cp WAVEDER WAVEDER.LOPTICS
cp OUTCAR OUTCAR-02
cp STDOUT STDOUT-02

# #######################step 3:  GW0 + WANNIER90  #################################

cat > INCAR << EOF

System  = SrVO3-gw0

ISMEAR = -5
NEDOS = 2000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states

NBANDS = 48                            # need for a lot of bands in GW

ALGO = GW0                             #
NELM = 1                               # one step so this is really G0W0
PRECFOCK = Fast                        # select fast mode for FFT's
ENCUTGW = 100                          # energy cutoff for response function
NOMEGA = 200                           # metal, we need a lot of frequency points
MAXMEM = 2500                          # memory per core
#NKRED = 2         # sample down the GW to a coarse 2x2x2 grid, for accuarate, comment out this iterm.

#KPAR = 3
ENCUT = 400
EOF

cp  WAVECAR.LOPTICS WAVECAR
cp  WAVEDER.LOPTICS  WAVEDER

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC > STDOUT

cp OUTCAR OUTCAR-03
cp STDOUT STDOUTi-03

# #######################step 3.1:  Analysis of the DOS   #################################

cat > INCAR << EOF

System  = SrVO3-gw0-dos

ISMEAR = -5
NEDOS = 2000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states

NBANDS = 48                           # need for a lot of bands in GW

ALGO = none                             #
NELM = 1                               # one step so this is really G0W0
PRECFOCK = Fast                        # select fast mode for FFT's
ENCUTGW = 100                          # energy cutoff for response function
NOMEGA = 200                           # metal, we need a lot of frequency points
MAXMEM = 2500                          # memory per core
#NKRED = 2                              # sample down the GW to a coarse 2x2x2 grid

#KPAR = 3
LORBIT = 11                           # for DOS
ENCUT = 400
EOF

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC > STDOUT

cp OUTCAR OUTCAR-03
cp STDOUT STDOUTi-03

# giving total.dat

./plotdos  

mv  total.dat  total-dos-afterGW0.dat

 
# #######################step 3.1:  Analysis of gw band, by using  LWANNIER90_RUN = .TRUE.  #################################

cat > INCAR << EOF

System  = SrVO3-gw0-band

ISMEAR = -5
NEDOS = 2000  # EMIN = -20 ; EMAX = 20 ; NEDOS = 1000 usefull energy range for density of states

NBANDS = 48                            # need for a lot of bands in GW

ALGO = none                             #
NELM = 1                               # one step so this is really G0W0
PRECFOCK = Fast                        # select fast mode for FFT's
ENCUTGW = 100                          # energy cutoff for response function
NOMEGA = 50                           # metal, we need a lot of frequency points,NOMEGA = 200
MAXMEM = 2500                          # memory per core
#NKRED = 2                              # sample down the GW to a coarse 2x2x2 grid

#KPAR = 3
#LORBIT = 11

LWANNIER90_RUN = .TRUE.     # for band calculation
ENCUT = 400
EOF

cat > wannier90.win << EOF

num_wann=24

num_bands=30

# for GW uncomment
exclude_bands 31-48

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

EOF

# start calculation

$PARA -n $NP -machinefile .nodelists.$$ $EXEC  > STDOUT
 
cp OUTCAR OUTCAR-01
cp STDOUT STDOUT-01
cp  wannier90_band.dat  wannier90_band-gw.dat