Which of the following does not exist ?

Options

A. primitive
B. body centered
C. face centered
D. end centered

Explanation

To solve the question "Which of the following does not exist?" regarding the types of unit cells in solid-state chemistry, we will analyze each option provided: primitive, body-centered, face-centered, and "and centered."

### Step-by-Step Solution:

1. **Understanding Unit Cells**:
- A unit cell is the smallest repeating unit in a crystal lattice that shows the full symmetry of the structure.

2. **Primitive Unit Cell**:
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