---
license: apache-2.0
tags:
  - water
  - MACE
  - molecular dynamics
  - extxyz
  - potential energy surface
language:
  - en
  - zh
---
<p align="center">
  <strong>
    <span style="font-size: 30px;">water</span>
  </strong>
</p>

## Dataset Description
The water dataset is an extxyz dataset for potential energy surface training and evaluation examples involving water systems. It contains atomic coordinates, unit-cell information, energies, and forces for water molecular systems in different configurations and is a standard benchmark dataset for developing and validating machine-learned interatomic potential methods such as MACE.

The original complete file `dataset_1593.xyz` contains 1,593 frames with 192 atoms per frame. To match the original MACE water configuration, this package follows the logic of the original `gene_xyz.py` to derive the first 1,393 frames from `dataset_1593.xyz` as the `water_train.xyz` training set and the final 200 frames as the `water_test.xyz` test set.

The original water training set comes from [BingqingCheng/ab-initio-thermodynamics-of-water](https://github.com/BingqingCheng/ab-initio-thermodynamics-of-water).

The current data package contains approximately 4 files totaling approximately 150 MB.

## Supported Tasks
This standardized data repository organizes the complete data package for the MACE water example, including the full dataset, training set, and test set, to support:
- Training and validation of potential energy surface models for water systems
- Potential energy surface fitting for molecular dynamics simulations
- Functional testing and benchmark evaluation of the MACE framework

## Dataset Format and Structure

The data files are located in the `data/water/` directory:

| File Path | Format | Shape / Content | Description |
|---|---|---|---|
| `water/dataset_1593.xyz` | extxyz | `[1593, 192]` | Full dataset, 1,593 frames with 192 atoms per frame |
| `water/water_train.xyz` | extxyz | `[1393, 192]` | Training set, the first 1,393 frames with 192 atoms per frame |
| `water/water_test.xyz` | extxyz | `[200, 192]` | Test set, the final 200 frames with 192 atoms per frame |
| `metadata/sha256_manifest.txt` | SHA256 | Checksum manifest | File integrity verification |

### extxyz Data Format

Each configuration consists of an atom-count line, a comment line, and atom lines. The comment line contains `TotEnergy`, `cutoff`, `nneightol`, `pbc`, `Lattice`, and `Properties`. Each atom line contains the element, coordinates, `force`, and `Z`.

| Field | Type | Shape | Description |
|---|---|---|---|
| `species` | str | `[N_atoms]` | Element symbols; the current set of elements is H and O |
| `pos` | float | `[N_atoms, 3]` | Atomic coordinates in Å |
| `force` | float | `[N_atoms, 3]` | Atomic forces in eV/Å |
| `Z` | int | `[N_atoms]` | Atomic numbers |
| `TotEnergy` | float | `[1]` | Total configuration energy in eV |
| `Lattice` | float | `[3, 3]` | Periodic cell matrix |
| `pbc` | bool | `[3]` | Periodic boundary conditions |

## How to Use the Dataset

Download the dataset:

```bash
hf download --dataset OneScience-Sugon/water --local-dir ./data
```


## Official OneScience Information

| Platform | OneScience Main Repository | Skills Repository |
|---|---|---|
| Gitee | https://gitee.com/onescience-ai/onescience | https://gitee.com/onescience-ai/oneskills |
| GitHub | https://github.com/onescience-ai/OneScience | https://github.com/onescience-ai/oneskills |

## Limitations and License

This dataset contains MACE water example data. The train/test split was derived from the full dataset using the logic of the original `gene_xyz.py`; no new samples were generated, and the original full dataset content was not altered. Refer to the original water data source and the information provided by the OneScience repository and ModelScope page for licensing terms.

When using the original water dataset, cite:

- Cheng, B.; Engel, E. A.; Behler, J.; Dellago, C.; Ceriotti, M. Ab Initio Thermodynamics of Liquid Water and Ice. *arXiv preprint* **2018**. https://arxiv.org/abs/1811.08630