[CPMD-list] Segmentation fault using Nose-thermostat

[Juerg Hutter]

Hi

the integrators have sometimes problems with the Nose
thermostats. This is especially true for the thermostats
on the electrons.
The integration diverges and at some point you get
segmentation faults.

The way out is to play with the NOSE PARAMETERS.
See also the manual (Hints and Tricks section).

The other problematic point may be the combination of
Constraints with Thermostats. Try to start your
job without the Constraints.
In principle this should be possible, but may need some
adjustments on the NOSE PARAMETERS and/or the way
you define your constraints.

regards

Juerg Hutter

----------------------------------------------------------
Juerg Hutter                   Phone : ++41 1 635 4491
Physical Chemistry Institute   FAX   : ++41 1 635 6838
University of Zurich           E-mail: hutter at pci.unizh.ch
Winterthurerstrasse 190
CH-8057 Zurich, Switzerland
----------------------------------------------------------


On Tue, 18 May 2004, Holger Hesske wrote:

> Dear users!
>
> After a lot of well running MD´s with TEMPCONTROL IONS, I´ve tried to use
> the Nose-Hoover-thermostat for producing proton-transfer in an ammonia-water
> bulk.
> But in any case (NOSE IONS.... NOSE ELECTRONS or both, even MASSIVE or
> ULTRA) the program stops with Segmentation fault.
> Every try leads to this error and I´m very appreciated if anybody could give
> me a hint. Maybe I´m missing something?
>
> Thanks in advance
> Holger
>
>
> Holger Heßke
> Institut für Anorganische Chemie
> TU DRESDEN
>
> The last lines in the output are
> ---
> Atomic coordinates and velocities are read from File Geometry
>
> *** PHFAC | the new size of the program is 74924 kBytes ***
> ---
> The input are for example:
>
> &CPMD
> FILEPATH /usr/local/CPMD/OUTPUTS/
>
> MOLECULAR DYNAMICS
> CONVERGENCE
>  1.0e-5 1.0e-4
> RESTART GEOFILE WAVEFUNCTION LATEST
> SPLINE POINTS
> 1500
> EMASS
> 600
> TEMPERATURE
> 400
> NOSE IONS MASSIVE
> 400.0 2500.0
> NOSE ELECTRONS
> 0.02 10000.0
> MAXSTEP
> 1000
> TRAJECTORY XYZ SAMPLE
> 10
> &END
> &SYSTEM
> ANGSTROM
> CELL ABSOLUTE DEGREE
> 10.0 10.0 10.0 90.0 90.0 90.0
> SYMMETRY
> 0
> POINT GROUP
> AUTO
> CHARGE
> 1
> CUTOFF
> 25
> 400eV
> SCALE
> TESR
> 1 1 1
> &END
> &DFT
> NEWCODE
> FUNCTIONAL BLYP
> GC-CUTOFF
> 1.0e-6
> &END
> &ATOMS
> H_SG_BLYP
> ....
> O_SG_BLYP
> ....
> N_SG_BLYP
> ....
> CONSTRAINTS
> ..
> ..
> END CONSTRAINTS
> &END
>
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