[xcrysden] how to identify k-space axes in Fermi Surface picture

[Kiyotaka Hammura]

Dear XCrySDen experts,

When we get Fermi Surface picture with XCrySDen, I do not know which
axis is which (in k-space).  Does anyone know how to know it or how to
draw 'axis labels', please?

Sincerely,
Kiyo