使用ligpargen在线得到了甲烷的itp文件，水使用tip4p-ice，在opls-aa力场进行，能量最小化正常结束，但每次正式模拟时就出现以下报错：
Warning: Only triclinic boxes with the first vector parallel to the x-axis and the second vector in the xy-plane are supported.
Box (3x3):
Box[ 0]={ nan, nan, nan}
Box[ 1]={ nan, nan, nan}
Box[ 2]={ nan, nan, nan}
Can not fix pbc.
Fatal error:
Step 100: The total potential energy is nan, which is not finite. The LJ and electrostatic contributions to the energy are 0 and 0, respectively. A non-finite potential energy can be caused by overlapping interactions in bonded interactions or very large or Nan coordinate values. Usually this is caused by a badly- or non-equilibrated initial configuration, incorrect interactions or parameters in the topology.