剛學(xué)qe,在做si的能帶和聲子計(jì)算時(shí)沒(méi)有任何錯(cuò)誤，但用si類似的輸入文件做ge和gaas時(shí)，碰到問(wèn)題了。
輸入文件如下：
+++++++++++++++++++++++++++++++
&control
     calculation = 'vc-relax'
          prefix = 'gaas'
          outdir = './outdir'
      pseudo_dir = '/home/work/pseudos'
   etot_conv_thr = 1e-5
   forc_conv_thr = 1e-4
/
&system
           ibrav = 2
       celldm(1) = 10.9
             nat = 2
            ntyp = 2
         ecutwfc = 50
         ecutrho = 600
/
&electrons
        conv_thr = 1.0e-14
/
&ions
/
&cell
     cell_dofree = 'ibrav'
/
atomic_species
ga 69.723   ga.pbe-dn-rrkjus_psl.1.0.0.upf
as 74.9216  as.pbe-n-rrkjus_psl.1.0.0.upf

atomic_positions (alat)
ga 0.00  0.00  0.00  0  0  0
as 0.25  0.25  0.25  0  0  0

k_points (automatic)
12  12  12  0  0  0
+++++++++++++++++++++++++++++++
&control
     calculation = 'scf'
          prefix = 'gaas'
          outdir = './outdir'
      pseudo_dir = '/home/work/pseudos'
   etot_conv_thr = 1e-5
   forc_conv_thr = 1e-4
/
&system
           ibrav = 2
       celldm(1) = 10.8704558116
             nat = 2
            ntyp = 2
         ecutwfc = 50
         ecutrho = 600
/
&electrons
        conv_thr = 1.0e-14
/
&ions
/
&cell
     cell_dofree = 'ibrav'
/
atomic_species
ga 69.723   ga.pbe-dn-rrkjus_psl.1.0.0.upf
as 74.9216  as.pbe-n-rrkjus_psl.1.0.0.upf

atomic_positions (alat)
ga 0.00  0.00  0.00
as 0.25  0.25  0.25

k_points (automatic)
12  12  12  1  1  1
++++++++++++++++++++++++++++++++
&control
     calculation = 'nscf'
          prefix = 'gaas'
          outdir = './outdir'
      pseudo_dir = '/home/work/pseudos'
   etot_conv_thr = 1e-5
   forc_conv_thr = 1e-4
/
&system
           ibrav = 2
       celldm(1) = 10.8704558116
             nat = 2
            ntyp = 2
         ecutwfc = 50
         ecutrho = 600
             nbnd = 8
        occupations = "tetrahedra'
/
&electrons
        conv_thr = 1.0e-14
/
&ions
/
&cell
     cell_dofree = 'ibrav'
/
atomic_species
ga 69.723   ga.pbe-dn-rrkjus_psl.1.0.0.upf
as 74.9216  as.pbe-n-rrkjus_psl.1.0.0.upf

atomic_positions (alat)
ga 0.00  0.00  0.00
as 0.25  0.25  0.25

k_points (automatic)
12  12  12  1  1  1
++++++++++++++++++++++++++
前面兩步計(jì)算好像沒(méi)有問(wèn)題，但到了nscf計(jì)算，就了出現(xiàn)不收斂的問(wèn)題。"too many bands are not converged"
之前做ge的計(jì)算時(shí)，也出現(xiàn)一樣的問(wèn)題，把贗勢(shì)從ge.pbe-dn-rrkjus_psl.1.0.0.upf改成ge.pbe-n-rrkjus_psl.1.0.0.upf就沒(méi)有問(wèn)題，
計(jì)算結(jié)果也可以和教科書一致。這是什么原因呢？
盼高手給以解答。
另外，雖然使用ge.pbe-dn-rrkjus_psl.1.0.0.upf計(jì)算vc-relax時(shí)沒(méi)有出現(xiàn)問(wèn)題，但迭代步數(shù)遠(yuǎn)多于使用ge.pbe-n-rrkjus_psl.1.0.0.upf。這是什么原因呢？ 返回小木蟲查看更多