[Pw_forum] Segmentaion fault and cell parameters

[Vishal Gupta]

Dear Piyush Sir,
I tried increasing parameter along z to 10.0 A but it didn't work. It still
works on 7 or less no of processors.

Regards
Vishal Gupta
B.Tech. 3rd year Mechanical
Indian Institute of Technology Ropar
Rupnagar (140001), Punjab, India.


On Wed, Aug 26, 2015 at 7:14 PM, Piyush Kumar <piyushkr1990 at gmail.com>
wrote:

> Dear Vishal,
> I think if you are not turning off the periodic boundary conditions, then
> your system is possibly wrong. By default QE works on periodic boundary
> conditions, so if you want to simulate a 2D system, then you should put
> some vaccum in the z direction, so that there is no interaction between
> periodic images. Maybe you can try increasing your cell parameter in z
> direction, say 10 Angstorm would be suffiecient, if it is only one atomic
> layer thick in z direction.
>
> With regards,
> Piyush Kumar,
> M.Tech. Student
> Indian Institute of Technology (IIT) Kanpur
> India
>
> On Wed, Aug 26, 2015 at 2:58 PM, Vishal Gupta <vishal.gupta at iitrpr.ac.in>
> wrote:
>
>> I've been running an SCF calculation for a free Ni system on High
>> performance cluster. The job runs fine with processors 7 or less but it
>> always leads to segmentation fault if the no of processors exceeds 7. The
>> job takes 4-5 days for the run.
>> I think the problem is in the definition of cell parameters in the input
>> file. Its a free lattice.
>> I have taken the cell parameters as :-
>> 22.6   0    0
>> 0   11.3   0
>> 0   0        1
>> and the extreme positions of the atoms in the model are :-
>> 0                0            0
>> 21.15282     0            0
>> 0                10.020    0
>> Its a single layer model. So along Z direction, its one atom thick layer.
>> Every dimension is in Angsrtom.
>> What should be the cell parameters for the model ?
>>
>>
>> Thank You for hearing my problem
>> Vishal Gupta
>> B.Tech. 3rd year Mechanical
>> Indian Institute of Technology Ropar
>> Rupnagar (140001), Punjab, India.
>>
>>
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>>
>
>
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