Graphene mechanics: I. Efficient first principles based Morse potential

Area of Science:

• Computational chemistry
• Materials science
• Nanotechnology

Background:

• Simulating large molecular systems like graphene and carbon nanotubes is computationally demanding.
• Accurate modeling of mechanical deformation and mixed systems (e.g., with biomolecules) requires efficient potentials.

Purpose of the Study:

• To develop a computationally efficient pairwise potential for molecular dynamics (MD) simulations.
• To enable simulations of large graphene/nanotube systems, including those under mechanical load and mixed with biomolecules.

Main Methods:

• The potential is based on the Morse potential, offering a balance between accuracy and computational cost.
• It is fitted to quantum mechanics (QM) data for bond breaking in graphene, with a dissociation energy of 805 kJ/mol.
• A key feature is truncation at the inflection point to realistically model ruptured C-C bonds without bond order models.

Main Results:

• The potential is only slightly more computationally expensive than harmonic potentials.
• It allows large or mixed simulations to reach experimentally relevant timescales.
• MD simulations using this potential show favorable agreement with experimental data and more complex potentials.

Conclusions:

• This new potential provides an efficient and accurate method for simulating complex carbon-based nanomaterials.
• It facilitates large-scale and mixed-system simulations, advancing research in materials science and nanotechnology.