<|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:
7.6 7.6 5.0
90 90 139
Na
0.65 0.19 0.00
Na
0.65 0.87 0.51
Na
0.00 0.00 0.00
Na
0.65 0.13 0.51
Na
0.65 0.81 0.00
Pb
0.65 0.00 0.51
Identify the crystal system.<|im_end|>
<|im_start|>assistant
Given the following crystal representation:
7.6 7.6 5.0
90 90 139
Na
0.65 0.19 0.00
Na
0.65 0.87 0.51
Na
0.00 0.00 0.00
Na
0.65 0.13 0.51
Na
0.65 0.81 0.00
Pb
0.65 0.00 0.51
Identify the crystal system.