Ab initio grand canonical Monte Carlo calculation of grain boundary composition and structure

The prediction of grain boundary structure has gained great attention in materials science because grain boundaries have a significant effect on material properties. However, the prediction of grain boundaries by multi-elemental systems has been difficult so far because the number of atoms and compositions are determined by a delicate energy balance between elements, which requires high calculation accuracy. Here, we have developed the ab initio grand canonical Monte Carlo (ai-GCMC) theory to grain boundaries, combining density functional theory and grand canonical Monte Carlo to overcome this problem, and apply this methodology to predict Ti segregation patterns in Ti-doped Σ13[1210](1014) α-Al2O3 grain boundaries. That is, we generated tons of Ti-segregated Al2O3 grain boundaries with DFT accuracy by GCMC and compare their free energy to determine the thermodynamically stable structure. Our prediction successfully corresponds with the experimentally observed structure, while providing..., All energy evaluations of grain boundaries were conducted using VASP software., , # Data from: Ab initio grand canonical Monte Carlo calculation of grain boundary composition and structure

[https://doi.org/10.5061/dryad.79cnp5j62](https://doi.org/10.5061/dryad.79cnp5j62)

## Description of the data and file structure

Program codes and xsf files for Al2O3 grain boundary structures generated by ab initio grand canonical Monte Carlo simulations.

Please see our manuscript for details.

### File: 2024\_08\_26\_aiGCMC\_Al2O3\_sigma13.zip

#### **`2024_08_26_aiGCMC_Al2O3_sigma13_Al*_Ti*`**

(ex. **_**Al2_Ti2 means the relative chemical potential of elements are -2 and -2 (eV/atom). Please see our publications for the details)

##### /temp_* 

the trial of GCMC simulations.

      **/temp_*/coord_accept.axsf**

The structure evolution of grain boundaries with the XCrySDen format. #0 shows atoms are in the grain boundary regions, #1 and #2 shows atoms are in the grain regions, and #3 shows atoms are in the buffer regions.

     **/temp_*/log.dat**

Log file for GCMC simu...