BB-BB(-1)-BB(+1)-SC improper dihedral definition

[WangLiguo-kyrie]

I define an BB-BB(-1)-BB(+1)-SC improper dihedral in martini3 force field, there is no warning in Martinize2 execution, but this definition is not applied in generated itp file.

This is the definition of BB-BB(-1)-BB(+1)-SC improper dihedral:

[ link ]
[ atoms ]
 BB {"resname": "PRO"}
-BB {"resname": $protein_resnames}
+BB {"resname": $protein_resnames}
SC1 {"resname": "PRO"}
[ dihedrals ]
BB -BB +BB SC1 2 -10 80 {"group": "BB-BB(-1)-BB(+1)-SC improper"}
[ edges ]
BB -BB
+BB SC1

[pckroon]

I think you're missing the edge BB +BB @fgrunewald do you know by heart whether dihedral definitions add edges?

[fgrunewald]

@pckroon they don't add edges; so if the edges are incorrect then it wouldn't work

[WangLiguo-kyrie]

I add BB +BB in [ edges], but it still doesn't work.

[pckroon]

Right, missed something. You shouldn't have an edge between SC1 and +BB, but between SC1 and BB instead. So your edges become:

[edges]
BB +BB
BB -BB
BB SC1

[WangLiguo-kyrie]

Got it! It works. Thank you!