<|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:
4.5 3.8 6.8
90 109 90
Si
0.30 0.00 0.47
Si
0.99 0.90 0.68
Pb
0.19 0.90 0.22
Cl
0.89 0.00 0.61
Identify the crystal system.<|im_end|>
<|im_start|>assistant
Given the following crystal representation:
4.5 3.8 6.8
90 109 90
Si
0.30 0.00 0.47
Si
0.99 0.90 0.68
Pb
0.19 0.90 0.22
Cl
0.89 0.00 0.61
Identify the crystal system.