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Article ID: 239 - Last Modified:

Do you have a table in which Lennard-Jones parameters of OPLS-2005 force field are given?

The OPLS parameter files store the epsilon and sigma Lennard-Jones parameters, rather than the A/B parameters. Also, only the per-atom parameters are stored (e.g., ei and ej); the actual L-J potential function parameters (e.g., eij) are computed as...

eij = sqrt(ei * ej)
sigmaij = sqrt(sigmai * sigmaj)

The OPLS_2005 ei and sigmai parameters can be found at


for the van der Waals atom types defined in


If you have MacroModel, you can view the Aij and Bij parameters for a specific structure via the Force Field Viewer (on the Tools menu). You'll first have to run a MacroModel Current Energy job with a Complete energy listing (on the ECalc tab). This will create the .mmo file that can be read by the Force Field Viewer. You should not run this type of job on a large structure (e.g., a protein), because the .mmo file will get very large.

Keywords: Lennard-Jones, parameters, OPLS, Force Field, Macromodel, Maestro

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