[gmx-users] No default Angle types

[Mark Abraham]

Darrell Koskinen wrote:
> Dear GROMACS Gurus,
> I received the following error when running grompp:
> /
> ERROR 0 [file "graphene.top", line 392284]:
>  No default Angle types
> /
> I believe this error is referring to the fact that there was no 
> definition of an angle type for the following combination of atoms:
> HA CA CT
> since line 392284 of the top file has this combination of atoms.
> 
> I took a look through the ffoplsaabon.itp file and saw that indeed there 
> was no definition for an angle between this combination of atoms. So I 
> thought that I could resolve this error by copying the ffoplsaabon.itp 
> file into my working directory, making a copy of the line for the CA CA 
> HA and renaming the combination CT CA HA. However, when I ran grompp 
> again, I still get the same error. Please advise.

Yes I believe that should work. You could also add a new [angletypes] 
directive into your .top file after the forcefield files to define this 
angle type. That might avoid any problems with ffoplsaa.itp needing to 
include the version of ffoplsaabon.itp local to your .top file rather 
than local to itself (if that's what's happening).

Mark