HW 1 Inorganic Materials
Chemistry
Name:
Points: C7780 Due date: 29.10.2019
Max. 100 points Fall 2019 A
1. (20 pts) In the crystalline Cu2O, oxygen atoms possess coordination number 4. What is the
coordination number of Cu? Show how you arrived to the answer.
2. (10 pts) A unit cell has in general shape of a) cube b) tetrahedron c) parallelepiped
3. (20 pts) Give stoichiometric formulas for the cubic structures in the picture below. a =
Heusler compound, b = Half-Heusler compound. Show how you arrived to the answer.
4. (25 pts) An octahedral structural unit CoO6 possesses following CoO bond distances (in
Å). Use Pauling Rules to establish whether the cobalt cation is in oxidation state 2+ or 3+.
Use parameters R0 = 1.692 Å and B = 0.30.
2x Co1–O1 2.1033(12)
2x Co1–O2 2.0703(12)
2x Co1–O3 2.1204(12)
5. (25 pts) Use the Born-Landé equation and the appropriate Shannon-Prewitt radii (provided
below) to calculate lattice energies (L0) for the following structures. Comment on results.
NaCl having the NaCl structure: rNa+
(CN6) = 1.16 Å; rCl–
(CN6) = 1.67 Å
NaCl having the CsCl structure: rNa+
(CN8) = 1.32 Å; rCl–
(CN6) = 1.67 Å (CN8 not avail.)