<|im_start|>system
Please reason step by step, and put your final answer within \boxed{}.<|im_end|>
<|im_start|>user
Given the following crystal representation:
4.0 4.0 5.9
90 90 91
Ca
0.00 0.00 0.00
Zn
0.81 0.33 0.97
Zn
0.81 0.67 0.97
Se
0.81 0.00 0.00
Identify the crystal system.<|im_end|>
<|im_start|>assistant
Given the following crystal representation:
4.0 4.0 5.9
90 90 91
Ca
0.00 0.00 0.00
Zn
0.81 0.33 0.97
Zn
0.81 0.67 0.97
Se
0.81 0.00 0.00
Identify the crystal system.