<|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:
3.6 3.6 8.7
90 90 90
Na
0.78 0.78 0.06
Na
0.78 0.78 0.64
Hg
0.00 0.00 0.00
Pb
0.00 0.00 0.35
Identify the crystal system.<|im_end|>
<|im_start|>assistant
Given the following crystal representation:
3.6 3.6 8.7
90 90 90
Na
0.78 0.78 0.06
Na
0.78 0.78 0.64
Hg
0.00 0.00 0.00
Pb
0.00 0.00 0.35
Identify the crystal system.