Atoms of elements `B` from hcp lattice and those of element `A` occupy two-thirds of tetrahedral voids. What is the formula of the compound formed by elements `A` and `B`?

Explanation

To determine the formula of the compound formed by elements A and B, we will follow these steps:

### Step 1: Understand the HCP Structure
Element B forms a hexagonal close-packed (HCP) lattice. In an HCP lattice, there are a total of 6 atoms per unit cell.

### Step 2: Calculate the Number of Atoms in HCP
In an HCP lattice:
- There are 12 corner atoms, each contributing \( \frac{1}{6} \) to the unit cell.
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