[CPMD-list] Restart Option for Wave Function & Geometry Optimizatio

[Ari P Seitsonen]

Dear Shashidhar,

   There seem to be some suspicious things in your input:

  - LMAX=P LOC=S does not make sense for a pseudo potential for silicon.
   LMAX=D (implying LOC=D) is the standard choice

  - This is a cluster of atoms, right? Are there degeneracies which might
   lead to dangling bonds being half filled? This could lead to zero
   electronic gap between the occupied and unoccupied states, and would
   lead to very slow or even impossible convergence

  - Why do you specify 'ORTHOGONALIZATION LOWDIN' and 'SPLINE POINTS'?

  - I personally find 'LBFGS' to be the fastest method for relaxing atomic
   coordinates

  - If you program stopped due to exceeding the computing time, it probably
   didn't produce a file "RESTART.1" yet, did it? If not, then you cannot
   perform a restart, and for the next job I would recommend either a
   smaller 'MAXSTEP' or checking out the option 'MAXCPUTIME' (please notice
   that the time specified has to be slightly smaller than the real time
   allowed by some machines, IBM included; I usually subtract 200-600
   seconds from the maximum time)

  - You can always perform 'RESTART WAVEFUNCTION COORDINATES LATEST',
   unless you have moved the file "RESTART.1" into "RESTART"

  - Did you try the input files which you provided? What went wrong, or did
   they work?

     Greetings,

        apsi

-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
   Ari P Seitsonen / Ari.P.Seitsonen at iki.fi / http://www.iki.fi/~apsi/
   IMPMC, CNRS & Université Pierre et Marie Curie
   Tel: +33-1-4427 7542, Fax: +33-1-4427 3785, GSM: +33-6-6736 3820

On Tue, 24 Apr 2007, Shashidhar G wrote:

> Dear All
>
> I'm running CPMD on IBM, AIX, power 4 ( 54 Nos. of 4-Way SMP nodes and 1 No.
> of 32-Way SMP node) for Si256 atoms.
> Here I'm attaching my input file for Wave Function optimization. I ran it
> with 16 processor (8 X 2), but I didn't achieved the self consistence
> criterion for wave function optimization and program stops due to wall clock
> time exceeded.
>
> I would like to Restart the calculation from last run. Here I'm giving my
> 1. Input File for Wave Function Optimization
Q> 2. Input File for Restart the Wave Function Optimization.
>
> Please Suggest me If I'm in wrong direction, and any thing is incorrect in
> both files 1 & 2 .
>
> -----------------------------------------------------------
> 1. Input For Wave Function Optimization.
> ------------------------------------------------------------
> &CPMD
> BFGS
> CENTER MOLECULE ON
> OPTIMIZE WAVEFUNCTION
> oPTIMIZE GEOMETRY
> ORTHOGONALIZATION LOWDIN
> rESTART WAVEFUNCTION COORDINATES LATEST
> rESTART ALL
> kOHN-SHAM ENERGIES
> 512
> CONVERGENCE ORBITALS
>  1.0D-7
> MAXSTEP
> 1000
> SPLINE POINTS
> 1000
> &END
>
> &DFT
> NEWCODE
> FUNCTIONAL LDA
> &END
>
> &SYSTEM
> ANGSTROM
> SYMMETRY
> 0
> CELL
> 33.507 1.0  1.0  0  0  0
> CUTOFF
> 17.56
> pOISSON SOLVER TUCKERMAN
> &END
>
> &ATOMS
> *SI.OUT1 KLEIMAN-BYLANDER
>  LMAX=P LOC=S
>  256
>           1.3575             1.3575             9.5025
>            0.0000             0.0000            10.8600
>            2.7150             0.0000            13.5750

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