<html><body><div style="color:#000; background-color:#fff; font-family:arial, helvetica, sans-serif;font-size:12pt"><div>Dear gmx users,</div><div><br></div><div>My .pdb input file has a formyl group which is not defined in CHARMM27 and CHARMM36. So I got its .itp file through swissparam. Now I want to use its parametrs. As I read in gromacs.org , I need to include this .itp in .top file. How does it come when I have not got any .top file yet?</div><div>Anybody can suggest me how I can use .itp file and solve my problem?</div><div><br></div><div>Thanks in advance,</div><div>Shima</div></div></body></html>