[gmx-users] Difference of LO and LOM atoms in lipid.itp for Gromacs force field

[Hector Mtz-Seara]

Dear all

I want to construct a carboxyl group (-COOH) to construct the Arachidic 
acid, and I'm using the extension atoms provided with the lipid.itp file 
its is correct to use this?

                             : -LC-LO
                                   |
                                LO-HO
what about LOW atom type?

For the hydrocarbon group which is a better atom type (LC2, LC3) or 
(LP2,LP3)?

Thanks in advance hector