Chain identifier should be blank not A: ATOM   2524 MG    MG A 312      42.990  57.550 355.030 31.00 54.30      A   MG  
Chain identifier should be blank not A: ATOM   2523 ZN    ZN A 313      42.350 310.880 557.100 71.00 30.40      A   ZN  

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