<|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:
11.3 11.3 11.3
15 15 15
Na
0.00 0.00 0.89
Na
0.00 0.00 0.60
Cr
0.00 0.00 0.00
Pb
0.00 0.00 0.75
Identify the crystal system.<|im_end|>
<|im_start|>assistant
Given the following crystal representation:
11.3 11.3 11.3
15 15 15
Na
0.00 0.00 0.89
Na
0.00 0.00 0.60
Cr
0.00 0.00 0.00
Pb
0.00 0.00 0.75
Identify the crystal system.