<|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:
3.0 3.0 8.5
90 90 90
Mg
0.00 0.00 0.66
Ru
0.00 0.00 0.40
Ru
0.51 0.51 0.91
Pb
0.51 0.51 0.75
Identify the crystal system.<|im_end|>
<|im_start|>assistant
Given the following crystal representation:
3.0 3.0 8.5
90 90 90
Mg
0.00 0.00 0.66
Ru
0.00 0.00 0.40
Ru
0.51 0.51 0.91
Pb
0.51 0.51 0.75
Identify the crystal system.