The crystal structure of lithium sulfide (Li2S) is pictured here. (Intro 1 figure) The edge length of the unit cell is 5.88*10^2^2 pm.

i guess it is FCC ( face cenred cubic)

1--

What are the coordination numbers of and Li^+ and S^2- in the lithium sulfide crystal shown? Enter the values in order of Li^+ and S^2-, respectively.

Ans... i though it shld be 4,4 .. but it says " Face ions are shared between two unit cells."...

plz someone

2- How many formula units are in the unit cell shown for ?

Ans- i gues it shld be 1 but it says -
The formula represents one formula unit. How many sets of are in the unit cell?

4 answers

for 2nd question ( shown for Li2S)
thnks

1. 4,8
2.4

4,8

2.=4