...
Summary | This initial approach started from the scripts and data left by Simon. Unfortunately, re-training vdW properties showed worse performance for Br molecules and pyridine molecules. Some experimentation with splitting out virtual sites showed that splitting the N vdW term into two improved performance. On examining the charges, it was observed that the charge of the pyridine virtual site was >1 in magnitude. It was decided to restrain the charge of the pyridine in a new fit to the initial valuesDigging into it, the documentation left by Simon was slightly incomplete and resulted in only training to some of the data, so a new re-fit and approach was started in Approach II. | ||||||
|---|---|---|---|---|---|---|---|
GitHub repo/branch | |||||||
Status |
|
...
Stage | Milestone/Benchmark | Contributors | Deadline | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Train virtual sites and BCCs to existing HF/6-31G* data | Re-fit 2.1.0 BCCs to ESP data | July 2023 |
| |||||||
Re-fit 2.1.0 BCCs and virtual sites to ESP data | July 2023 |
| ||||||||
Re-fit valence and vdW parameters to condensed phase properties | Re-fit FF terms for no-vsites-candidate | Aug 2023 |
| |||||||
Re-fit FF terms for vsites-candidate | Aug 2023 |
| ||||||||
Benchmark | Improved or equivalent performance for molecules with virtual sites added (Cl, Br, pyridines) on training data |
| ||||||||
Experiment with vdW site splitting to see if that improves benchmarks | Sept 2023 |
| ||||||||
Experiment with fitting to dimer energies | Sept 2023 |
| ||||||||
Benchmark | Improved or equivalent performance for molecules with virtual sites added (Cl, Br, pyridines) on training data |
|
...
Unfortunately, properties with bromine and pyridine virtual sites have a decrease in performance.
Splitting out vdW terms
Splitting the N vdW term into two, and fitting to dimer energies resulted in improved performance on training data.
...