How to add urea as a cosolvent in gromacs?

I have tried to add urea as a cosolvent for my system by using the following command: genbox -cp tmp.xtc.gro -ci urea.gro -nmol 423 -o ureamix.gro -p topol.top And it shows File input/output...

13 June 2018 8,695 4 View