many thanks for your new ressources on your homepage ! ...is it possible that it does not make sense to try to optimize a 2,2,2trifluoroethanol molecule model for the (current) additive Charmm force field in stead of waiting for the next generation of force fields that will allow for explicit representation of polarization effects (which could be expected to be quite important in 2,2,2trifluoroethanol/water mixtures as fluor atoms are extremely electrophilic)? If not: how much time would you say is necessary if I start as a beginner in parametrization to build a more suitable TFE model for building good TFE/water boxes which can reproduce experimental properties more accurately ?
it will take a good amount of time as you will need to do a careful optimization of the LJ parameters, which is the most difficult aspect of the FF to optimize. I suggest you take the current model and do condensed phase simulations in different conditions for which experimental data is available. the absolute values for the empirical model may not be correct, but if you are getting the trends correct, that should be adequate for your needs.
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In the tutorial of forcefiled parameters for new molecules, where i could run all the inp files except model_b_molvib_g03.inp and showing an error
charmm/c32b1/exec/gnu/charmm < model_b_molvib_g03.inp > model_b_molvib_g03.out fmt: end of file apparent state: unit 12 named fort.12 last format: (20A4) lately reading sequential formatted external IO Abort
how could i rectify it and how to see the optimized charges.