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WMD-group / hybrid-perovskites

DFT optimised crystal structures of inorganic and hybrid halide perovskites
GNU General Public License v2.0
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How to know the right High-symmetry points.? #1

Open niaozhishi74 opened 3 years ago

niaozhishi74 commented 3 years ago 
 Thanks for your hybrid-perovskites structure files first.  
 But there is a question,when I want to calculate the band structure，the line-mode KPOINTS file seems in trouble。Because the structure parameters have been changed after your structure relaxation，the vaspkit or the https://www.materialscloud.org/work/tools/seekpath get the wrong spacegroup and the High-symmetry points。So how can I get the right High-symmetry points with your files ，or should I just ignore the mistake？
aronwalsh commented 3 years ago

Hi @niaozhishi74. That is one problem of these materials. The average spacegroup symmetry is not recovered by a static structure. It is only found in a time or spatial average.

In our perspective, we made this point which may help you:

"While the labels of the special points are those of the cubic perovskite structure (space group Pm3m), the static model of the hybrid perovskite formally has P1 symmetry. Points equivalent for a cubic crystal are inequivalent here."

In most halide perovskite publications, the standard cubic labels are used: R (1/2,1/2,1/2), M (1/2,1/2,1/2) and X (1/2,0,0).