How the miller indice of the certain plane in primitive setting of a crystal change when I use POSCAR-SURFACE given by wanniertools

[shuvajit31416-netizen]

the question relates to how the POSCAR-SURFACE is created, If I have a plane with certain miller index suppose ( 1 -1 0), and I create a POSCAR-SURFACE for the surface card which has plane ( 1 1 1). then how the miller index of (1 -1 0) plane will change.