[gmx-users] DPPC lipid model in Gromos 53a5
mark.abraham at anu.edu.au
Mon Mar 3 14:21:35 CET 2008
> Dear all,
> In the definition of the DPPC lipid molecule in ffG53a5.rtp I found, that
> dihedral angles are defined twice:
> [ dihedrals ]
> ; ai aj ak al gromos type
> C33 N C32 C31 gd_29
> N C32 C31 O32 gd_4
> N C32 C31 O32 gd_36 <-
> C32 C31 O32 P gd_29
> C31 O32 P O31 gd_20
> C31 O32 P O31 gd_27 <-
> O32 P O31 C3 gd_20
> O32 P O31 C3 gd_27 <-
> Is this a mistake or on purpose ?
> Does the second entry overwrite the first entry, i.e. the values of the
> entry are used ?
It depends on the functional form - you'll need to look up these gd_??
macros in the forcefield .itp file. A second function with the same
function type will over-write the first. I think it does so silently. A
different function type on the same atoms is accepted silently.
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