[gmx-users] Virtual Sites + Capped Termini

[Joan Clark Nicolas]

Dear gmx users,

I am trying to simulate a protein-ligand system in gromacs 5.1 with capped
termini and using Virtual Sites.
When I try to generate the tpr file with grompp, it seems that it is
missing some constraint parameters for the bonds of C from ACE and N from
NME with their respective virtual sites. The error I am receiving is the
one that follows:


*ERROR 1 [file topol.top, line 8967]:*
*  No default Constr. No Conn. types*


*ERROR 2 [file topol.top, line 8968]:*
*  No default Constr. No Conn. types*


*ERROR 3 [file topol.top, line 9505]:*
*  No default Constr. No Conn. types*


*ERROR 4 [file topol.top, line 9506]:*
*  No default Constr. No Conn. types*

where errors 1 and 2 correspond to ACE C-VS bonds and errors 3 and 4
correspond to NME N-VS bonds. Can you tell me what am I doing wrong?

Thank you very much!

*Joan Clark i Nicolas*