# Phase transitions in titanium with an analytic bond-order potential

## TL;DR

This paper develops an efficient analytic bond-order potential for titanium, enabling large-scale simulations of phase transitions and defects with accuracy comparable to first-principles methods.

## Contribution

It introduces a new bond-order potential for Ti derived from a coarse-grained tight-binding approach, suitable for large-scale and finite-temperature simulations.

## Key findings

- The BOP accurately predicts structural properties of Ti phases.
- The model effectively simulates martensitic transformations.
- Computational efficiency is significantly improved over first-principles methods.

## Abstract

Titanium is the base material for a number of technologically important alloys for energy conversion and structural applications. Atomic-scale studies of Ti-based metals employing first-principles methods, such as density functional theory, are limited to ensembles of a few hundred atoms. To perform large-scale and/or finite temperature simulations, computationally more efficient interatomic potentials are required. In this work, we coarse grain the tight-binding (TB) approximation to the electronic structure and develop an analytic bond-order potential (BOP) for Ti by fitting to the energies and forces of elementary deformations of simple structures. The BOP predicts the structural properties of the stable and defective phases of Ti with a quality comparable to previous TB parametrizations at a much lower computational cost. The predictive power of the model is demonstrated for simulations of martensitic transformations.