Question about magnon band structure from TB2J output

[陶冶]

Dear Dr. He

I have a problem about calculating magnon band structure of BCC-Fe. When I use the command,

TB2J_magnon.py --qpath GNPGHN --figfname magnon.png --show

(This command is written in the website https://tb2j.readthedocs.io/en/latest/src/magnon_band.html), the program will return error and tell me the K-path do not have G, N, and H points. However, when I do not use qpath tag, 

TB2J_magnon.py --figfname magnon.png --show

I can get the magnon band structure of BCC-Fe. So I think the program may not get correct high-symmetry points. However, I have no idea about how to solve this problem and I hope that you can give me some advice.  

Your advice on these matters would be immensely helpful in resolving my confusion and advancing my work. Thank you in advance for your time and assistance. I look forward to your response.

Tao Ye