[gpaw-users] Dipole correction breaks restart

[Ask Hjorth Larsen]

Hi Andy

On Wed, 13 Oct 2010, Andrew Peterson wrote:

> Hi again,
>
> I've discovered that implementing the dipole correction breaks the
> restart function of the GPAW calculator. I've attached a simple script
> that has a dipole correction. Trying to use restart('calc.gpw') on the
> output file results in the below error. (This doesn't happen on the same
> script if the dipole parts are removed.)
>
> thanks,
> Andy
>
> ===== Error message from gpaw.restart:
> >>> from gpaw import restart
> >>> atoms, calc = restart('calc.gpw')
>
>  ___ ___ ___ _ _ _
> |   |   |_  | | | |
> | | | | | . | | | |
> |__ |  _|___|_____|  0.7.6383
> |___|_|
>
> User: aap at suncat0073
> Date: Wed Oct 13 15:31:34 2010
> Arch: x86_64
> Pid:  6584
> Dir:  /afs/slac/g/suncat/vol1/gpawv3/install/lib64/python/gpaw
> ase:   /afs/slac/g/suncat/vol1/gpawv3/ase/ase  version:  3.4.1
> numpy:
> /afs/slac/g/suncat/vol1/gpawv3/numpy-1.4.1/build/lib.linux-x86_64-2.4/numpy
> units: Angstrom and eV
> Memory usage: 23.12 MB
> Traceback (most recent call last):
>  File "<stdin>", line 1, in ?
>  File
> "/afs/slac/g/suncat/vol1/gpawv3/install/lib64/python/gpaw/__init__.py",
> line 261, in restart
>    calc = Class(filename, **kwargs)
>  File
> "/afs/slac/g/suncat/vol1/gpawv3/install/lib64/python/gpaw/paw.py", line
> 116, in __init__
>    self.initialize()
>  File
> "/afs/slac/g/suncat/vol1/gpawv3/install/lib64/python/gpaw/paw.py", line
> 580, in initialize
>    par.external)
>  File
> "/afs/slac/g/suncat/vol1/gpawv3/install/lib64/python/gpaw/hamiltonian.py",
> line 69, in __init__
>    self.poisson.set_grid_descriptor(finegd)
>  File
> "/afs/slac/g/suncat/vol1/gpawv3/install/lib64/python/gpaw/poisson.py",
> line 52, in set_grid_descriptor
>    self.operators = [Laplace(gd, scale, self.nn, allocate=False)]
>  File
> "/afs/slac/g/suncat/vol1/gpawv3/install/lib64/python/gpaw/fd_operators.py",
> line 154, in Laplace
>    return NewGUCLaplace(gd, scale, n, dtype, allocate)
>  File
> "/afs/slac/g/suncat/vol1/gpawv3/install/lib64/python/gpaw/fd_operators.py",
> line 270, in __init__
>    coefs = [laplace[n][0] * a_d.sum()]
> IndexError: list index out of range
>
>
>
> ===== Input script:
> #!/usr/bin/env python
>
> from ase.data.molecules import molecule
> from ase.visualize import view
>
> from gpaw import GPAW
> from gpaw.poisson import PoissonSolver
> from gpaw.dipole_correction import DipoleCorrectionPoissonSolver
>
> atoms = molecule('H2O')
> atoms.set_cell([12.,12.,12.])
> atoms.center()
>
> p = PoissonSolver()
> calc = GPAW(txt='H2O.txt',
>            poissonsolver=DipoleCorrectionPoissonSolver(p, 2),
>           )
>
> atoms.set_calculator(calc)
>
> energy = atoms.get_potential_energy()
>
> calc.write('calc.gpw')
>
>
> _______________________________________________
> gpaw-users mailing list
> gpaw-users at listserv.fysik.dtu.dk
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>

Yes, the restart code is not aware of dipole corrections.  You're more 
than welcome to fix it.  Another possibility is to supply a new Poisson 
solver when restarting:

   calc = GPAW(filename, poissonsolver=OtherPoissonSolver())

By the way, it would probably be wise to verify that e.g. the dipole 
moment of water corresponds to the correct shift in potential for a dipole 
moment of that size.  (I'll keep suggesting this until someone actually 
does it :))

Regards
Ask