<|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:
4.2 4.0 6.9
90 107 90
Be
0.00 0.00 0.00
Tl
0.97 0.00 0.30
Bi
0.14 0.01 0.25
Bi
0.02 0.01 0.34
Identify the crystal system.<|im_end|>
<|im_start|>assistant
Given the following crystal representation:
4.2 4.0 6.9
90 107 90
Be
0.00 0.00 0.00
Tl
0.97 0.00 0.30
Bi
0.14 0.01 0.25
Bi
0.02 0.01 0.34
Identify the crystal system.