Hi! pls help me :p.

To determine its formula, count all sorts of atoms inside the unit cell, also considering fractional atoms which belong to more than one unit cell. For example, an atom at the corner of the unit cell counts as 1/8 atom because it is shared between 8 adjacent unit cells. Likewise, an atom at the edge of the unit cell counts as 1/4 as it belongs to 4 unit cells etc. When you obtain fractional values for the atom numbers, multiply the values of all atoms with a certain number so that all values are integers.