[gmx-users] Including and itp file, for a residue

[chris.neale at utoronto.ca]

Another possibility:
Where are your included files (lipid.itp, dmpc.itp)?
They must be in the current directory or the regular top directory or you can 
set GMXDATA or just give the full path of all included files in the #include "/
path/x.itp" statement.