Padam Bahadur Chetry

Dear All, I have been newly introduced to potfit . And I am not bale to make out the refernce data format . if any one can help me ,what the reference data to be given and which format.

Dear all, I have been newly introduced to potfit .And I am not able to understand the reference data format for potfit. If any one can help me in which format the refernce data are to be supplied.