Energy correction for isolated impurities under periodic boundary conditions

Area of Science:

• Condensed matter physics
• Computational materials science
• Solid-state physics

Background:

• Calculating Coulomb energy in infinite, disordered systems is computationally challenging.
• The supercell method often requires large system sizes to minimize finite-size effects.
• Accurate treatment of electrostatic interactions is crucial for understanding material properties.

Purpose of the Study:

• To present a novel energy correction method for the supercell approach.
• To enable accurate calculation of Coulomb energy in isolated, infinite aperiodic systems.
• To improve the efficiency and practicality of simulations for disordered materials.

Main Methods:

• Developed an energy correction term for the supercell method.
• Investigated direct (charge distribution interactions) and indirect (multipole expansion) approaches for the correction.
• Performed test calculations on various impurity types (isotropic, anisotropic, neutral).

Main Results:

• Obtained impurity energies that are independent of supercell size.
• Demonstrated the effectiveness of the energy correction for different impurity charge distributions.
• Validated the method's ability to simulate isolated disorder in infinite systems.

Conclusions:

• The proposed energy correction method accurately calculates Coulomb energy for aperiodic systems.
• This technique overcomes limitations of standard supercell methods for disordered materials.
• The approach is applicable to arbitrary systems, facilitating more practical computational simulations.