The unit cell of a substance has cations `A^(+)` at the corners of the unit cell and anions `B^(-)` in the centre. What is the simplest formula of the substance ?

Explanation

To determine the simplest formula of the substance based on the given unit cell structure, we can follow these steps:

### Step 1: Identify the position of cations and anions
In the unit cell, we have cations \( A^+ \) located at the corners and anions \( B^- \) located at the center.

### Step 2: Calculate the contribution of cations
Cations \( A^+ \) are located at the corners of the unit cell. Each corner contributes \( \frac{1}{8} \) of a cation to the unit cell because each corner is shared by 8 adjacent unit cells. Since there are 8 corners in a cube, the total contribution from the cations is:
\[
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