[CPMD-list] Help:about ag cutoff!

[=?gb2312?B?wu3J0NLl?=]

Dear CPMD user:
     I want to specify the suitable Ag cutoff energy and compute the single point total energy with different cutoff, I find it's difficult to converge with the criteria 1d-6 no matter what arithmetic I use. The Ag pesudopential file is Ag_SEMI_BLYP.psp under the pseudo-ext folder. The table show the results:

Ag_SEMI_BLYP.psp  a=4.086 Å  converge criteria  1d-6
* indate it does't converge when it reach the maxmum number step
 





 

£Å£Î£Å£Ò£Ç£Ù£¨A.U.£© (the number of computation step     time/s)


CUTOFF

PCG MINIMIZE

DEFAULT

LANCZOS DIAGONALIZATION

STEEPEST DESCEND

ODIIS- LANCZOS


20

-148.65459706
(2521  129s)

-148.62911313*
(    234s)

-148.62911313*
(     234s)

-148.63166745*

-148.65454618*
(    238s)


30

-150.48724701
(902    73s)

-150.48724701
(2529  103s)

-150.48724701
(2529  103s)

-150.48724593*

-150.48694426*
(    411s)


40

-150.58035561
(2986   306)

-150.58035560
(5742  281s)

-150.58035560
(5742  281s)

-150.58009052*

-150.58008550*
(    495s)


50

-150.58300390
(2166  363)

-150.58272049
(5065  399s)

-150.58272049
(5065  399s)

-150.58272548*

-150.58300309*
£¨£©


60

-150.58499425
(2231  408)

-150.58471114
£¨5679  490s£©

-150.58471114
(5679  493s)

-150.58493776*

-150.58480024*
(    880s)


70

-150.58628042
(1958  449)

-150.58622285*
(   1126s)

-150.58622285*
(    1126s)

-150.58627646*

 


80

-150.58682224
(2060  627s)

-150.58682223
(1649  244s)

-150.58682223
(1649  245s)

-150.58681380*

 


90

-150.58693002
(6863  2500s)

-150.58665354*
(    1605s)

-150.58665354*
(     1615s)

-150.58665277*

 


100

-150.58697361
(4912  2619s)

-150.58671318*
(    1939s)

 

-150.58680340*
(    1934)

 


110

-150.58699188
(1647  707s)

-150.58699187
(5925  1248s)

-150.58699187
(5925  1253s)

-150.58672231
(    2092s)

 


120

-150.58701175
(2112  1342s)

-150.58672938*
(     3316s)

 

-150.58680001*

 


130

-150.58701943
(644   433s)

-150.58701942
(77   27s)

-150.58701942
(77   26s)

-150.58701942
(6653    )

 


140

-150.58702605
(3426  2472s)

-150.58702605
(4539 1588s)

 

-150.58700999*

 


150

-150.58703046
(1468  1187s)

-150.58674744
(5322  2050s)

 

-150.58684764*
(     3830s)

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
And you can find that the computation time is very short if I specify  the cutoff  130 Ry, but it's difficult to converge in other casese! The following is my main form of input file:
&CPMD
 OPTIMIZE WAVEFUNCTION
 CONVERGENCE ORBITALS
 1.0D-6
 PRINT FORCES ON
 PCG MINIMIZE
 TIMESTEP
 20
 MIRROR
&END
&DFT
 FUNCTIONAL BLYP
&END
&SYSTEM
 SYMMETRY
 FCC
 SCALE
 ANGSTROM
 CELL
 4.086  1.0  1.0  0  0  0
 CUTOFF
 20
&END
&ATOMS
*Ag_SEMI_BLYP.psp
 LMAX=D
 1
 0.00   0.00   0.00
&END

I appreciate that  if you find something wrong with the input file and it should be corrected or if you have some advice to improve the effiency of the computation!
Thank in advance  and best wishes!
                                                                              shyma
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