[gmx-users] ForceField for SDPC(sphingomyelin)

[linfu]

Dear Gmx community

I am new to memberane simulation. i want to simulate membrane,
which consists DPPC and SDPC(Sphingomyelin). luckily, i got the
force field and coordinates for DPPC (dppc.itp,dppc.pdb) from
Doctor Peter Tieleman'websites.however,i cannot find the force 
field and coordinates for SDPC. could anyone kindly share with me 
the file above or point me to right website or reference.

Thank you very much

Fu lin