Question

Nomenclature Of Phenol with examples and with IUPAC And With common name

Answer 1

Your diffractometer program will suggest you some cells and symmetries, however, with your structure solution program you can check for the cell with the highest symmetry fitting your dataset (beware of twinning :)) and you will see, which of the candidates is the best.Well there is Z and Z'. Z is the number of formula units in your unit cell.  Z' is the number of asymmetric units. This is  Z divided by the lowest multiplicty in your list of Wyckoff positions. Sometimes, the formula unit is easy to see, as in salts or molecular compounds and many other simple structures with small unit cells. As the size of the unit cell grows, however, Z becomes somewhat arbitrary, depending on the unit you define.