2021-03-12 WBO/Impropers meeting notes

Participants:

@Christopher Bayly

@David Mobley

@Pavan Behara

@Trevor Gokey

@Simon Boothroyd

@Jessica Maat (Deactivated)

Discussion:

• Make sure to use the average improper angle, not improper angle calculated in a single way

• Do a check of :

  • Improper applied three fold

  • Improper applied using the avg. improper angle

  • See if they are mathematically equivalent

• Categorize the grid optimization datasets by planar, flat and intermediate (DM suggestion)

  • Try to come up with parameters based on these categorizations

  • Perform a fit on these

• CB suggests looked at urea and seeing a potential around 3-5 kcal/mol and compare to amides which have a squishy improper angle

• SB suggests try labeling the impropers with current FF and use these as a starting point for developing impropers

• Redo example of wbo vs improper barrier, see if there is a correlation

  • start with a small example

  • see how torsion, valence and improper angles correlate

• Try to do a refit for a specific chemistry

  • refit the torsion, improper and valence simultaneously

  • select maybe, sulfur improper, then check which molecules in grid opt and torsion dataset its applied, use these as targets for a refit