Re: [Spglib-users] Irreducible k points from custom k mesh

[Atsushi T. <atz...@gm...>]

Hi,

Your questions are not about spglib. I can probably answer them, but
I'm afraid that my answers will invite more questions. Then coding it
by myself for you will be much easier for me than answering. I want to
save my time.
You can also find the information not from me, but from your
supervisors or colleagues. In case that you can unfortunately not find
people around you, I can recommend reading this book,
https://www.cambridge.org/core/books/symmetry-and-condensed-matter-physics/218B3D7B149076E63A618D4584E3379B.

Togo

On Mon, Jun 21, 2021 at 1:59 AM cheng shao <sha...@gm...> wrote:
>
> Dear Prof. Togo,
>
> Thanks for your reply. I was thinking about using the rotation symmetry operator to find the irreducible k points from the k point list.
>
> For example, I want to apply the symmetry operator to find all the duplicates of the current k_point and check if any of them is in the irreducible k point list.
>
> However, I am a bit confused about how the rotation symmetry operator should be used.
>
> In the get_symmetry section, it says
> new_vector[3x1] = rotation[3x3] * vector[3x1] + translation[3x1]
>
> While in the definitions and conventions section, there is an equation:
> (𝐚̃ ,𝐛̃ ,𝐜̃ )=(𝐚,𝐛,𝐜)𝑊
>
> Should I use the rotation * k_point, or using k_point * rotation?
> Do I need to apply some modifications like inversion and transpose to the rotation matrix before applying it to the k points?
>
> Sorry for bothering you again, and I am appreciated if you could help me out here.
>
> Best,
> Cheng
>
>
>
> On Sun, Jun 20, 2021 at 5:42 PM Atsushi Togo <atz...@gm...> wrote:
>>
>> Hi,
>>
>> No. It's not possible.
>> But it is trivial to implement.
>>
>> Togo
>>
>> On Sun, Jun 20, 2021 at 4:13 PM cheng shao <sha...@gm...> wrote:
>> >
>> > Dear Prof. Togo,
>> >
>> > I am a new user of the spglib, and thanks for your efforts in developing and maintain it.
>> >
>> > I have a quick question: is it possible to find the irreducible k points from the custom-defined k mesh?
>> >
>> > Say I have a uniform k mesh points (in a different order as the auto-generated one from spglib),
>> > Is it possible to identify the irreducible k points and the weight factor from it.
>> >
>> > In the example, there is a function `grid = get_ir_reciprocal_mesh(mesh, cell, is_shift=[0, 0, 0])`,
>> > can we replace the integer number mesh to a vector of k points?
>> >
>> > Best,
>> > Cheng
>> > ----
>> > Dr. Cheng Shao
>> > Post-Doctoral Researcher
>> > Dept. of Mechanical Engineering
>> > The University of Tokyo
>> >
>> >
>> >
>> > _______________________________________________
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>> > Spg...@li...
>> > https://lists.sourceforge.net/lists/listinfo/spglib-users
>>
>>
>>
>> --
>> Atsushi Togo
>>
>>
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-- 
Atsushi Togo