A compound of formula `A_(2)B_(3)` has the hcp lattice. Which atom forms the hcp lattice and what fraction of tetrahedral voids is occupied by the other atoms

Options

A. hcp lattice-B, `(2)/(3)` Tetrachedral voids-A
B. hcp lattice-A, `(2)/(3)` Tetrachedral voids-B
C. hcp lattice-A, `(1)/(3)` Tetrachedral voids-B
D. hcp lattice-B, `(1)/(3) underset(h rarr 0 )(lim)` Tetrachedral voids-A

Explanation

`A_(2) B_(3)` is in HCP lattice
If lattice formed by B then number of tetrahedral voids per B atom = 2
Fraction of TVs filled = `(2)/(6) = (1)/(3) `
If lattice formed by A then number of tetrahedral voids per A atom = 2
Fraction of TVs filled = `(3)/(4)`