[gmx-users] Conversion of Harmonic potential parameters to Morse potential parameters

[Jashimuddin Ashraf]

Dear gromacs users,

I have a system containing carbon nanotubes. I have successfullly simulated
the system in vacuum. Now i would like to terminate the dangling bonds of
the nanotube with Hydrogen atoms. So, I need to modify my forcefield.

In the [ bondtypes ] section inside my forcefield.itp I had

;
[ bondtypes ]
CJ    CJ      3    0.1418   478.9000   21.867

;

Now I need to add the bond parameters for carbon-Hydrogen. But
unfortunately I have my parameters in Harmonic potential; instead of Morse
potential. How can I convert my Harmonic potential parameters to Morse
potential parameters? Is there any formula for this?

Thanks in advance