<|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:
5.2 5.2 5.2
135 135 65
Na
0.00 0.00 0.00
Ag
0.00 0.00 0.42
Ag
0.00 0.00 0.21
Os
0.00 0.00 0.21
Identify the crystal system.<|im_end|>
<|im_start|>assistant
Given the following crystal representation:
5.2 5.2 5.2
135 135 65
Na
0.00 0.00 0.00
Ag
0.00 0.00 0.42
Ag
0.00 0.00 0.21
Os
0.00 0.00 0.21
Identify the crystal system.