What is the coordination number of `TVs` and `OV s`

Explanation

To determine the coordination number of tetrahedral voids and octahedral voids, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Coordination Number**:
- The coordination number refers to the number of nearest neighboring atoms or ions that surround a central atom or ion in a crystal structure.

2. **Tetrahedral Voids**:
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