(Solved): Homework-4: Interstitial Sites Problem 1: For the BCC unit cell, (a). Indicate all of the positions ...

Homework-4: Interstitial Sites Problem 1: For the BCC unit cell, (a). Indicate all of the positions of Octahedral Interstices, the total number of Octahedral atoms in one unit cell, the diameter (usually expressed as the radius ratio $r_X/r_A,X$ interstitial atom, A lattice atom) of the atoms which just fit into the Octahedral Interstices. (b). Indicate all of the positions of Tetrahedral Interstices, the total number of Tetrahedral atoms in one unit cell, the diameter (usually expressed as the radius ratio $r_X/r_A,X$ interstitial atom, A lattice atom) of the atoms which just fit into the Tetrahedral Interstices. Problem 2: What is the difference between octahedral interstices in FCC unit cells and octahedral interstices in BCC unit cells? Please explain the difference in terms of the symmetry, diameter (usually expressed as the radius ratio $r_X/r_A,X$ interstitial atom, $A$ lattice atom), and the position of those octahedral interstices. Problem 3: For the simple cubic unit cell, (a). Indicate the type interstices, the total number of interstices atoms in one unit cell, the diamete (usually expressed as the radius ratio $r_X/r_A,X$ interstitial atom, $A$ lattice atom) of the atoms which just fit into the Interstices. 13 Crystal Structure of Some Simple Inorganic Compounds AX: Rock Salt, Cesium Chloride, Zinc Blende ${\mathrm{A}}_m{\mathrm{X}}_{\mathrm{n}}$ : Fluorite $\left({\mathrm{CaF}}_2\right)$