I have plotted the band structure of a tetragonal crystal lattice having space group symmetry p421m using ATK with unit cell dependent route (default route as given by the ATK VNL). In the band structure plot I have seen that the energy values for gamma and Z, R and X are same. In most cases for a tetragonal crystal lattice X, gamma, M and X points are only considered so I want to know, if I do not consider R, X point will it create any problem in band structure? What is the reason behind chosing of these high symmetry points (Z, R) for band structure?