[QE-users] Symmetry Operations in Reciprocal Space

[Ankit Sharma]

Hi,
A follow up question:
I used two different systems with the same point group symmetry. I used the
same density of the Monkhorst Pack grid of 8x8x6. But the resultant number
of reduced k vectors when using nosym=.false. and noinv=.false. are
different?
As mentioned in the previous post, I am trying to manually reduce the k
point grid into the irreducible set of k points using the symmetry
Operations that is printed in the output of the scf calculation?
Can some suggest me what is it that I am doing wrong?

Thank You,
Ankit Sharma

On Thu, Mar 21, 2019, 13:04 Ankit Sharma <ankitub31 at gmail.com> wrote:

> Thank you sir, I was able to figure it out.
> Thank you for all the help.
>
>
> Thanks
> Ankit Sharma
> University at Buffalo
>
> On Thu, Mar 21, 2019, 08:04 Ankit Sharma <ankitub31 at gmail.com> wrote:
>
>> Hi,
>> I am sorry for the sloppiness.
>> I generated a list of k points setting nosym and noinv to TRUE in scf
>> calculation for a system with 2/m point group symmetry. I also generated
>> the k point list with full symmetry consideration by setting the above two
>> flags to FALSE.  Apart from identity, there are 3 more symmetry Operations
>> with inversion, 180° rotation and inv. 180° rotation.
>>
>> Now I apply the symmetry operation of the point group manually to the
>> list of k points with no symmetry and try to match the output with that of
>> the symmetry reduced k point list generated above.
>>
>> The number of points obtained don't match. I get more points than that
>> generated by QE with full symmetry consideration. Am I conceptually wrong?
>>
>> Thanks
>> Ankit Sharma
>> University at Buffalo
>>
>>
>>
>> On Wed, Mar 20, 2019, 22:53 Ankit Sharma <ankitub31 at gmail.com> wrote:
>>
>>> Hi,
>>> This question might be trivial; I have a set of k points spanning the
>>> full BZ and I want to reduce it to the IBZ. So for that, I used the point
>>> group symmetry Operations to reduce the k points. But I am not able to
>>> match the reduced number of k points that I calculate to the output from QE.
>>> Any help would be appreciated.
>>>
>>> Thank You,
>>> Ankit Sharma
>>> University at Buffalo
>>>
>>
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