luda 电子结构计算除了能量带外，还是状态密度，是经常计算的电子特性、状态密度计算的正式教程。
基本参数设置是prtdos, prtdosm两个参数:
prtdos =1 :smeared DOS从本征值中获取，所有的能级都被考虑，分布根据occopt和tsmear，occopt在3-7之间，如果是半导体，先在自洽时使用0-2，然后非自洽计算密度，iscf=-3,包括金属性质的occopt。
prtdos =2：使用四面体方法计算DOS，使用不偏移的网格（shiftk 0 0 0），不必考虑occopt的值，计算需进行自洽和非自洽的计算。
prtdos = 3: 同样使用四面体方法，加入了角动量投影的计算，要加入3个变量，natsph, iatsph, ratsph。natsph为要计算PDOS的原子数，默认为总原子数，iatsph为natsph原子的索引，ratsph是原子半径，参考原子数据文件，r_paw，在PAW情况下，原子半径要大于等于原子类型中最大的，另外，pawprtdos =2用于近似一个较好的DOS。
prtdos=4: 基于prtdos=1的方法计算球形投影态密度，
prtdos=5：自旋-自旋态密度，适用于nspinor=2, 使用四面体方法（tetrahedron method）。
prtdosm =1or 2: 仅当prtdos=3时使用。
算例：
#Specific input parameters related to DOS printing
#Case 1: Total DOS
prtdos 1 # Flag to activate the total DOS output
#Case 2: projected DOS (to be uncommented later)
#prtdos 3 # Flag to activate the projected DOS output
#pawprtdos 1 # Flag to activate the output of all PAW contributions
#natsph 1 # Number of atom(s) around which the projected DOS has to computed
#iatsph 1 # Index of these atoms
#ratsph 1.51 # Radius defining the projection area around the atom(s)
#For this calculation we take a metallic scheme for the occupation numbers
#This is mandatory for a DOS calculation
occopt 7 # Automatic generation of occupation numbers, as a metal
tsmear 0.005 # Smearing temperature for the metallic occupation scheme (Hartree)
#For this calculation we take more k-points to have a smoother DOS curve
ngkpt 10 10 10 # This is a 10x10x10 grid based on the primitive vectors
#-------------------------------------------------------------------------------
#The rest of this file is similar to the file
# using the ecut and pawecutdg values deduced from the convergence studies
#Definition of the unit cell
acell 3*3.567 angstrom # Lengths of the primitive vectors (exp. param. in angstrom)
rprim # 3 orthogonal primitive vectors (FCC lattice)
0.0 1/2 1/2
1/2 0.0 1/2
1/2 1/2 0.0
nsym 0 # Automatic detection of symetries
#Definition of the atom types and pseudopotentials
ntypat 1 # There is only one type of atom
znucl 6 # Atomic number of the possible type(s) of atom. Here carbon.
pseudos "Pseudodojo_paw_pw_standard; # Name and location of the pseudopotential
#Definition of the atoms
natom 2 # There are two atoms
typat 1 1 # They both are of type 1, that is, Carbon
xred # Location of the atoms:
0.0 0.0 0.0 # Triplet giving the reduced coordinates of atom 1
1/4 1/4 1/4 # Triplet giving the reduced coordinates of atom 2
#Definition of bands and occupation numbers
nband 6 # Compute 6 bands (4 occupied, 2 empty)
#Numerical parameters of the calculation : planewave basis set and k point grid
ecut 12.0 # Maximal plane-wave kinetic energy cut-off, in Hartree
ecutsm 0.5 # Introduce a smooth PW cutoff within an 0.5 Ha region (not used here)
pawecutdg 24. # Max. plane-wave kinetic energy cut-off, in Ha, for the PAW double grid
kptopt 1 # Automatic generation of k points, taking into account the symmetry
nshiftk 4 # of the reciprocal space, repeated four times,
shiftk # with different shifts:
0.5 0.5 0.5
0.5 0.0 0.0
0.0 0.5 0.0
0.0 0.0 0.5
#Parameters for the SCF procedure
nstep 20 # Maximal number of SCF cycles
tolvrs 1.0d-10 # Will stop when, twice in a row, the difference
# between two consecutive eValuations of potential residual
# differ by less than tolvrs
#Miscelaneous parameters
prtwf 0 # Do not print wavefunctions
prtden 0 # Do not print density
prteig 0 # Do not print eigenvalues该结果输出总DOS，如果输出PDOS，则选择Case2, 打开prtdos 3和pawprtdos，输出的结果有_DOS_AT000*文件，如果安装了Xmgrace可以用下列命令画出DOS：
xmgrace -block tpaw1_4o_DOS_AT0001 -bxy 1:7 -bxy 1:12 -bxy 1:17我下载不了Xmgrace，所以就使用了gnuplot作图，其命令如下，可以根据自己的数据做出修改，移动了费米能级，转化了能量单位为eV：
plot "<(sed -n '17,7417p' sro_DOS_TOTAL)" u (($1-0.303489)*27.2113845):($2) w l ,"<(sed -n '7421,14821p' sro_DOS_TOTAL)" u (($1-0.303489)*27.2113845):($2)) w l这里有gnuplot的中文教程，,可以一起学习。