# Explicit Solvation Benchmark Packet (Public Export)

Date: March 5, 2026  
Packet ID: `explicit_solvation_benchmark_packet_2026-03-05`

## Packet Metadata

| Field | Value |
|---|---|
| Module | `Explicit Solvation` |
| Benchmark | `Water Hydration Free Energy` |
| Dataset | `FreeSolv v0.52 screening subset` |
| Cases | `642` |
| Public export timestamp (UTC) | `2026-03-05T22:00:25Z` |
| Sanitized public export | `true` |

## Headline Metrics

| Metric | Value |
|---|---:|
| MAE (kcal/mol) | `0.3295` |
| RMSE (kcal/mol) | `0.4593` |
| MAE (kJ/mol) | `1.3787` |
| RMSE (kJ/mol) | `1.9219` |
| Pearson r | `0.9928` |
| R squared | `0.9857` |
| Median absolute error (kcal/mol) | `0.2427` |
| Max absolute error (kcal/mol) | `2.4019` |
| Within uncertainty fraction | `0.7492` |

## Coverage Statement

- Externally benchmarked in this packet: Water (TIP3P/TIP4P family).
- Additional production native explicit carriers included as regression coverage in this packet:
  - Methanol
  - Ethanol
  - Acetonitrile
  - DMSO

## Largest Remaining Error Regions (n >= 10)

| Chemotype | n | MAE (kcal/mol) |
|---|---:|---:|
| halophenol_like | 11 | 0.5812 |
| chlorinated_hydrophobe | 22 | 0.4713 |
| phenolic_polar_aromatic | 30 | 0.4178 |
| monohaloalkane_long | 17 | 0.4095 |
| alkoxy_rich | 11 | 0.4017 |
| hydrophobe | 36 | 0.3756 |

## Top Absolute Error Cases

| Case ID | Chemotype | Abs Error (kcal/mol) |
|---|---|---:|
| mobley_5732611 | general | 2.4019 |
| mobley_3325209 | general | 2.4012 |
| mobley_2763835 | hydrophobe | 1.6854 |
| mobley_2751110 | phenolic_polar_aromatic | 1.6367 |
| mobley_1178614 | halophenol_like | 1.5996 |

## Public Artifact Hashes (SHA256)

| Artifact Label | File | SHA256 |
|---|---|---|
| benchmark summary | `explicit_solvation_benchmark_summary_2026-03-05.json` | `de11039e500c8babf22951d9fd0ea54532ac0453dfa0e226dc496d9f2a96e5a2` |
| case table csv | `explicit_solvation_benchmark_cases_2026-03-05.csv` | `c53288a3abe3ef0821e0e5d944dd1b5d7a9713656bb9a7d022470949820d9b9f` |
| case table json | `explicit_solvation_benchmark_cases_2026-03-05.json` | `f6e52f8991d1a59ed29f42ad820e458b62e9ea8224251e32864b5bc45cde6741` |
| error breakdown note | `explicit_solvation_error_breakdown_2026-03-05.md` | `f94e874eb37ecc944239c1a4fe6979b4a5b4a0d8b8bd0486d52a925755c22bc2` |
| methodology note | `explicit_solvation_methodology_2026-03-05.md` | `14dff3f9af086b98fc9ef31e961efddd5c7cd3d40e8bc807b4ee8c8994acd061` |
| packet manifest json | `explicit_solvation_benchmark_packet_2026-03-05.json` | `81f6d29c6cda25f09841cc954fa9e3a9d2b9d4ec2244f2341b2966d5e05dfe44` |

Public export note: internal implementation details (local paths, internal script names, and internal parameter naming) are intentionally omitted.