A unit cell has several interstitial voids (or spaces or sites). There are two types of interstitial voids in FCC and BCC cells, namely, octahedral and tetrahedral. However, the octahedral and tetrahedral voids in BCC are not regularly shaped but distorted. Describe, along with a sketch, where the centre of the "distorted" octahedral voids are located in a BCC cell. With the aid of your sketch, calculate the number of "distorted" octahedral voids in the BCC cell. State how many"distorted" tetrahedral voids are there in a BCC cell.