Which of the following crystal is represented by `a ne b ne c` and `alpha ne beta ne gamma ne 90^(@)` ?

Options

A. Orthorhombic
B. Monoclinic
C. Triclinic
D. Tetragonal

Answer

To solve the question, we need to identify which crystal system is represented by the conditions: \( a \neq b \neq c \) and \( \alpha \neq \beta \neq \gamma \neq 90^\circ \).

### Step-by-Step Solution:

1. **Understanding the Notation**:
- The letters \( a, b, c \) represent the lengths of the edges of the crystal unit cell.
- The angles \( \alpha, \beta, \gamma \) represent the angles between these edges.

2. **Identifying the Conditions**:
- The conditions given are:
- \( a \neq b \neq c \): This means that all three edge lengths are different.
- \( \alpha \neq \beta \neq \gamma \neq 90^\circ \): This means that all three angles are different and none of them is 90 degrees.

3. **Analyzing the Crystal Systems**:
- **Orthorhombic**: In this system, \( a \neq b \neq c \) but \( \alpha = \beta = \gamma = 90^\circ \). So this does not fit our conditions.
- **Monoclinic**: Here, \( a \neq b \neq c \) and \( \alpha = \gamma = 90^\circ \) while \( \beta \neq 90^\circ \). This does not fit our conditions either.
- **Tetragonal**: In this system, \( a = b \neq c \) and \( \alpha = \beta = \gamma = 90^\circ \). This does not fit our conditions.
- **Triclinic**: In this system, \( a \neq b \neq c \) and \( \alpha \neq \beta \neq \gamma \neq 90^\circ \). This fits our conditions perfectly.

4. **Conclusion**:
- The crystal system that satisfies the conditions \( a \neq b \neq c \) and \( \alpha \neq \beta \neq \gamma \neq 90^\circ \) is **Triclinic**.

### Final Answer:
The correct option is **Triclinic**.