An alloy of copper and gold crystallizes in cubic lattic, in which the `Au-` atoms occupy the lattice points at the corners of cube and `Cu-` atoms occupy the centre of each face. The formula of this alloy is `:`

Explanation

To determine the formula of the alloy of copper (Cu) and gold (Au) that crystallizes in a cubic lattice, we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Positions of Atoms in the Unit Cell:**
- The problem states that gold (Au) atoms occupy the lattice points at the corners of the cube.
- Copper (Cu) atoms occupy the center of each face of the cube.

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