A methodology for coupling an atomic model with a continuum model using an extended Lagrange function

Area of Science:

• Computational physics
• Materials science
• Condensed matter physics

Background:

• Simulating complex materials often requires balancing atomistic detail with computational efficiency.
• Existing models may struggle to capture large-scale fluctuations and emergent phenomena in hybrid systems.

Purpose of the Study:

• To develop a novel hybrid method integrating atomic and continuum models.
• To investigate large-scale fluctuations and phonon behavior in a hybrid system.
• To enable efficient, large-scale simulations of materials.

Main Methods:

• Extended Andersen's Lagrange function for constant-pressure molecular dynamics.
• Incorporated continuum displacement field as a new degree of freedom.
• Applied the method to a one-dimensional hybrid model (atomic chain and springs).

Main Results:

• Observed significant large-scale fluctuations in the hybrid atomic system.
• Derived the phonon density of states, showing a variety of generated states.
• Demonstrated the capability for large-scale simulations with reduced computational cost.

Conclusions:

• The proposed hybrid method effectively captures complex atomic fluctuations.
• The methodology facilitates the generation of diverse phonon states.
• This approach offers a computationally efficient way to perform large-scale materials simulations.