Data Publication: Exfoliation and Cleavage of Crystals from a Universal Potential

<strong>Primary Research Data for "Exfoliation and Cleavage of Crystals from a Universal Potential"</strong>

<em>Tom Barnowsky &amp; Rico Friedrich<br>
TU Dresden &amp; Helmholtz-Zentrum Dresden-Rossendorf, Germany</em>

This dataset contains the primary data supporting the publication "Exfoliation and Cleavage of Crystals from a Universal Potential". Each directory corresponds to a bulk entry from the AFLOW database for which a slab prediction was generated. The directory name follows the AFLOWLIB uniform resource locator (with the prefix `aflowlib.duke.edu:` omitted). Bulk data can be retrieved from aflowlib.duke.edu through the AFLOW REST API using this identifier [1].

Within each bulk directory, subdirectories are provided for every predicted slab. Their names follow the pattern:

<pre><code class="language-bash">ID="${MILLER_INDEX}_facet_${BULK_CHEMICAL_FORMULA}_ICSD_${BULK_ICSD_NUMBER}_slab_${SLAB_CHEMICAL_FORMULA}_uff_${UFF_ENERGY}"</code></pre>

Chemical formulas are alphabetically ordered.
UFF energies [2] are written with two significant figures.

This provides a unique identifier for every bulk/slab configuration.

<strong>Contents of Each Slab Directory</strong>

Each `${ID}` directory contains:

`POSCAR.vasp.xz`: structure file of the unrelaxed predicted 2D slab.
If an exfoliation-energy calculation was performed, the full AFLOW/VASP calculation data is included [3-8].
A static "as-sliced" DFT calculation is located in a separate `${ID}_static` directory.
If a DFT calculation did not finish cleanly the calculation data is omitted.

For systems where band structures or molecular dynamics (MD) were computed, the respective results are stored as:

`${ID}/BANDS_DOS`
`${ID}/MD_300K`

<strong>Directory Structure Example</strong>

Below is an example for the predicted (001) slab of BaCO₃:

<pre><code>AFLOWDATA
└── ICSD_WEB
├── HEX
│ ├── Ba1C1O3_ICSD_91897
│ │ ├── 001_facet_Ba1C1O3_ICSD_91897_slab_Ba1C1O3_uff_0.75
│ │ │ ├── aflow.in
│ │ │ ├── BANDS_DOS
│ │ │ │ ├── aflow.in
│ │ │ │ └── ...
│ │ │ ├── MD_300K
│ │ │ │ ├── INCAR.xz
│ │ │ │ └── ...
│ │ │ └── ...
│ │ └── 001_facet_Ba1C1O3_ICSD_91897_slab_Ba1C1O3_uff_0.75_static
│ │ ├── aflow.in
│ │ └── ...
│ └── ...
└── ...</code></pre>

This structure is split at the third level into 14 separate tar archives (one for each Bravais lattice) for download.

<strong>Structure File</strong>

Each `POSCAR.vasp.xz` file contains the predicted slab structure in VASP's POSCAR format. The file header encodes essential metadata about the algorithm and parameters used to generate the slab.

<em>HKLSEARCH Slabs</em>

For slabs created using the HKLSEARCH algorithm, the header has the form:

<pre><code class="language-bash">HEADER="Slab( ${H} ${K} ${L} ), start=${START}, thickness=${THICKNESS}, energy=${SURFACE_ENERGY}, ratio=${IN_OUT_RATIO}"</code></pre>

where

`START`: Starting point of the cut-out layer along the (hkl) normal in units of Angstrom.
`THICKNESS`: Thickness of the extracted slab along the (hkl) normal in units of Angstrom.
`SURFACE_ENERGY`: The XCP model surface energy (divided by 2).
`IN_OUT_RATIO`: The in-plane/out-of-plane ratio.

<em>BONDDEL Slabs</em>

For slabs created using the BONDDEL algorithm, the header is:

<pre><code class="language-bash">HEADER="Slab(bonddel, ${H} ${K} ${L}), ratio=${RATIO}"</code></pre>

where

 `RATIO`: 2D/3D cut bond energy ratio.

<strong>Additional Files</strong>

This dataset also includes the potential data file used with the FINDSLAB code [9], supplied as `POTDATA_morse_yukawa_2025.xz`.

<strong>License</strong>

This dataset is published under the Creative Commons Attribution 4.0 (CC BY) license. We kindly ask works based on this data to cite this dataset entry and/or the associated publication.