<|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:
3.4 3.4 6.7
90 90 90
Nb
0.68 0.68 0.46
Nb
0.68 0.68 0.20
Tl
0.00 0.00 0.33
W
0.00 0.00 0.00
Identify the crystal system.<|im_end|>
<|im_start|>assistant
Given the following crystal representation:
3.4 3.4 6.7
90 90 90
Nb
0.68 0.68 0.46
Nb
0.68 0.68 0.20
Tl
0.00 0.00 0.33
W
0.00 0.00 0.00
Identify the crystal system.