2021-08-11 AM1 Studies Meeting notes

Date

Aug 11, 2021

Participants

  • @Jeffrey Wagner

  • @Connor Davel

  • @Owen Madin

Discussion topics

Item

Notes

Item

Notes

Presentation prep/feedback

  • OM – In “triangle plots”, make sure to fully explain right when you get to the slide

  • OM – On histogram slide, highlight the “percent-past-cutoff” number, maybe put a bright red box

  • Slide 13 and 15 – Fix modified method name in legend, cover figure title with something better not refer to “previous two plots”

  • Slide 21 – Change cutoff to 0.05 if it’s easy

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Talk feedback

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    • JW – Can we actually try to choose a good charge model to reproduce MD observables WITHOUT retraining the entire FF? It seems like any new charge model we try to propose will be plagued by the fact that the FF was trained with the OLD charge model.

    • CD – Right now, the FF was trained using OE charges. Long term, the only way would be to retrain FF repeatedly to try and reproduce observables.

 

  • CC – Also, I’m curious, when you do the MM constrained minimizations, I wonder how those results would change with a solvent model

  • DM – Could we set up a electrostatics meeting with Simon, Bayly, and Schauperl (if we can get him)?

    • OM – We should do this / get Bayly’s feedback on this.

Update project map?

Next steps

  • OM – Could pursue one question about reproducing “gold standard”, and another questions about “ideal restraint schemes”

    • CD – Agree.

    • JW – For first point – reproducing “gold standard” in cases where connectivity doesn’t rearrange – I’d need a lot of convincing that vanilla antechamber AM1 isn’t the gold standard. I don’t think there’s a “more golden” standard for AM1 charge generation than vanilla antechamber.

    • CD – Conformer dependence? If the user gives us one conformer, what if a different conformer would produce a better set of charges? Would a good partial charge method in that case choose a DIFFERENT conformer? How do we control for that?

    • JW – One assumption that we’re making in all of this work is that all conformers of a molecule should give “good” charges

    • CD – Maybe differences in the geometry minimization are the cause of all the partial charge differences that we see between antechamber and openeye.

      • JW – I think this is the case

  • OM – We should talk with Bayly, Boothroyd, Schauperl about this. Especially we should show bayly the cases where there aren’t connectivity rearrangements, and there’s a big difference between OE and original.

    • CD – I can show him the input conformers and the antechamber final geometries, but I can’t show him the OE final geometries.

    • OM – That’s fine, Bayly can look at those internally.

  • JW – We’ve reached a good point for a deliverable for the toolkit - the maxcyc=0 fallback is now statistically justified. CD made

  • CD – GeomeTRIC long term outlook?

    • GeomeTRIC isn’t looking great. Current implementation is very slow, tends to explode, and can’t handle many restraints. So it may be good to look into doing something different, and possibly make the tools to check these directions out. Or I could look into geomeTRIC and see if there’s some way to make it more stable, or make it run sqm/antechamber cycles faster.

  • JW – Kinda three major direction to proceed:

  • JW will upload today’s recording and share with OM

  • OM will contact Bayly, Schauperl, Booythroyd

  • CD will open a PR to OpenFF toolkit that includes

    • a simple test case of connectivity change and ensures that it gets caught,

    • updates the conn. change checker to use RDKit,

    • updates docs/developing.md to have a quick summary of the study (and figure), the conclusion, and a link to more info on confluence

Action items

Decisions