<|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:
5.0 5.0 5.0
137 137 61
Nb
0.00 0.81 0.15
Al
0.00 0.00 0.00
Cr
0.81 0.00 0.15
Cr
0.00 0.00 0.31
Identify the crystal system.<|im_end|>
<|im_start|>assistant
Given the following crystal representation:
5.0 5.0 5.0
137 137 61
Nb
0.00 0.81 0.15
Al
0.00 0.00 0.00
Cr
0.81 0.00 0.15
Cr
0.00 0.00 0.31
Identify the crystal system.