## 2.3 The Simplified Force Field

The "mm2gp" type project is for simplified protein models[1].

Protein molecules are modelled using 1-3 "virtual atoms" per amino acid residue in this kind of model. Several chains and disulphide brides are supported, but non-natural amino acids are not. Files can be imported in the PDB file format. The force field is fully functional with an initial parameter set, and algorithms for geometry optimization and molecular dynamics are available.

There are no sophisticated tools for model building yet, but they might be coming later.

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