[CPMD-list] Convergence Problem with USPP!

[=?gb2312?q?Adrain=20Zhou?=]

Dear all,
 
I downloaded the pseudopotential of Scandium from Vanderbilt page. I just performed a single atom or dimer calculation to check this USPP. I use PCG to optimize the wavefunction. But even for a single atom, the convergence is very slow.  The total energy sometimes suddenly increase and sometimes decrease for both LSD and LDA calculation. I don't know why. It should not be the problem of a small ECUTOFF because I have also tried a larger one. The input file is as follows,
 
&CPMD
  OPTIMIZE WAVEFUNCTION
  rESTART WAVEFUNCTION COORDINATES LATEST
  LSD
  PCG
  CONVERGENCE
  1.D-5  1.D-4
  MAXSTEP
  80
&END
&DFT
  NEWCODE
  FUNCTIONAL BP
  GC-CUTOFF
  5.D-5
&END
&SYSTEM
  ANGSTROM
  SYMMETRY
  8
  CELL
  10.0 1.0  1.0  0  0  0
  CUTOFF
  30.0
&END
&ATOMS
*021-Sc-gpw-nsp-campos.uspp NEWF BINARY
   LMAX=D
   1
  0.000  0.000  0.0000
&END

 
The CPMD output is as follows,
 
  4  3.403E-02   8.916E-03     -45.602951   -7.321E-01      7.30
   5  2.888E-02   6.970E-03     -45.974281   -3.713E-01      5.85
   6  2.762E-02   5.491E-03     -46.177619   -2.033E-01      6.92
   7  2.367E-02   4.301E-03     -46.328164   -1.505E-01      7.35
   8  2.352E-02   3.909E-03     -46.437055   -1.089E-01      8.48
   9  2.763E-02   6.736E-03     -46.412699    2.436E-02      7.35
  10  7.245E-02   1.144E-02     -46.202682    2.100E-01      6.79
  11  9.437E-02   1.393E-02     -45.993694    2.090E-01      7.83
  12  9.629E-02   1.406E-02     -45.910707    8.299E-02      6.77
  13  8.807E-02   1.296E-02     -45.920446   -9.740E-03      6.67
  14  9.071E-02   1.080E-02     -45.966492   -4.605E-02      6.83
  15  9.638E-02   8.175E-03     -45.980198   -1.371E-02      6.31
  16  9.359E-02   6.555E-03     -45.897131    8.307E-02      7.77
  17  8.267E-02   6.863E-03     -45.745599    1.515E-01      6.88
  18  6.752E-02   7.745E-03     -45.585839    1.598E-01      7.13
  19  5.158E-02   8.487E-03     -45.457233    1.286E-01      7.51
  20  3.854E-02   8.974E-03     -45.372361    8.487E-02      5.96
  21  4.417E-02   9.255E-03     -45.326675    4.569E-02      6.59
  22  4.827E-02   9.397E-03     -45.309583    1.709E-02      5.98
  23  5.110E-02   9.451E-03     -45.310703   -1.120E-03      7.55
  24  5.369E-02   9.454E-03     -45.325597   -1.489E-02      5.47

 
Could anyone tell me what's wrong with it? Many thanks!
 
Regards,
Zhou




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