刚学qe,在做si的能带和声子计算时没有任何错误，但用si类似的输入文件做ge和gaas时，碰到问题了。
输入文件如下：
+++++++++++++++++++++++++++++++
&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
++++++++++++++++++++++++++
前面两步计算好像没有问题，但到了nscf计算，就了出现不收敛的问题。"too many bands are not converged"
之前做ge的计算时，也出现一样的问题，把赝势从ge.pbe-dn-rrkjus_psl.1.0.0.upf改成ge.pbe-n-rrkjus_psl.1.0.0.upf就没有问题，
计算结果也可以和教科书一致。这是什么原因呢？
盼高手给以解答。
另外，虽然使用ge.pbe-dn-rrkjus_psl.1.0.0.upf计算vc-relax时没有出现问题，但迭代步数远多于使用ge.pbe-n-rrkjus_psl.1.0.0.upf。这是什么原因呢？ 返回小木虫查看更多