I have used the attached python script (got it from internet) to create CONFIG file for TIP4P with 216 molecules in cubic boundary condition. I have made some changes in the original script. When I compared results of newly created CONFIG file with example of TIP4P given in DL_POLY 4, there was a huge difference. All inputs were same in the comparison except CONFIG files. 

Can anyone check whether my CONFIG file is correct for TIP4P?