[MMTK] spring constant value in Ca force field

Konrad Hinsen research at khinsen.fastmail.net
Tue May 5 05:33:03 UTC 2015

Enrico Guarnera writes:

 > What is the value set for spring constant c in mmtk Ca force field?
 > I’m referring to the constant c in equation (8) of ’98 Hinsen’s
 > paper. Is it 1 kj/mol/nm^2?

The force field described in that paper is called
DeformationForceField in MMTK. Its documentation at


gives the full functional form, with the default for the prefactor as
46402.0 kJ/mol/nm^2. I don't remember where that particular number
comes from.

Note that the CalphaForceField is something different, it's described
in the paper

Hinsen, K., Petrescu, A., Dellerue, S., Bellissent-Funel, M. C., & Kneller, G. R. (2000).
Harmonicity in slow protein dynamics.
Chemical Physics, 261(1-2), 25–37.

Konrad Hinsen
Centre de Biophysique Moléculaire, CNRS Orléans
Synchrotron Soleil - Division Expériences
Saint Aubin - BP 48
91192 Gif sur Yvette Cedex, France
Tel. +33-1 69 35 97 15
E-Mail: research AT khinsen DOT fastmail DOT net
ORCID: http://orcid.org/0000-0003-0330-9428
Twitter: @khinsen

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