<|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:
3.1 3.1 6.8
90 90 90
Ca
0.00 0.00 0.13
Ni
0.53 0.53 0.43
Ni
0.00 0.00 0.50
Pt
0.53 0.53 0.06
Identify the crystal system.<|im_end|>
<|im_start|>assistant
Given the following crystal representation:
3.1 3.1 6.8
90 90 90
Ca
0.00 0.00 0.13
Ni
0.53 0.53 0.43
Ni
0.00 0.00 0.50
Pt
0.53 0.53 0.06
Identify the crystal system.