[gmx-users] Dihedrals Parametrization in the .rtpf File

[Lara Bunte]

Hi

I have three questions: 


1.)

If you create a .rtp file in your force field folder (I use charmm27) you have a block [ dihedrals ] with the structure

[ dihedrals ] 


atom1    atom2    atom3    atom4    phi0    cp      mult


What is cp and what is mult? 


2.)

In the [ impropers ] block you have

[ impropers ]


atom1      atom2      atom3      atom4     q0     cq

What is q0 and cq?

3.)
Out of a supporting information of a paper I have the information "improper dihedral angles" I have the four atoms and force constants and equilibrium angles. What is the syntax for thin in my .rtp file? Do I use [ dihedrals ] or [ impropers ] block or how do I write my Information in gromacs in my rtp. file? 


Thanks for help
Greetings
Lara