Is it possible to mix a coarse grained force field with an all-atom one?

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1

GROMACS version:
GROMACS modification: Yes/No
Here post your question I am preparing input files to simulate a few proteins (CG), added to an Au nanoparticle (atomistic). The files for the proteins are prepared in martini force field and the nanoparticle in all-atom. Performing the simulation, I receive an error regarding to “two defaults directives” in itp file:

[ defaults ]
1 1

; Following line is added by me, from the itp file of the nanoparticle
1 2 yes 1.000000 1.000000

and, well, it doesn’t like two defaults.
I read in one of the discussions that “it is impossible to run a simulation with two force fields”. Is that right? If that isn’t the case, how can I get around this error?

2

Hi, in the literature there are several papers where Au nanoparticles are modeled using MARTINI. They will come up easily in a search, and I would start by reading what they did.

Giacomo

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