RSPt tutorial 7: Inter-atomic exchange parameters Jij's (Practice)

Summary

This script offers a detailed tutorial on performing spin-polarized DFT and LSD+U calculations for magnetic materials, including cobalt-iron-aluminum, nickel oxide, and hcp terbium. It covers generating k-point meshes, creating input files for Jij calculations, and analyzing results for exchange interactions. The tutorial emphasizes the importance of using appropriate projections, tailoring the cluster block for different materials, and interpreting calculated Jij values for understanding magnetic interactions.

Takeaways

• 🔍 The folder number seven contains several examples for spin polarized DFT calculations for different materials.
• 📂 Examples include calculations for cobalt, iron, aluminum, nickel oxide, and a rare earth system, focusing on exchange interactions.
• 💻 A program called init_jijs is included to generate input green files for these calculations.
• 🧲 The first example involves a converged calculation for a material with cobalt and iron atoms, focusing on magnetic moments.
• 🔄 A k-point mesh is generated to sample the entire Brillouin zone, modifying the symmetry operations as needed.
• 📑 The green input files are created using a script that identifies intrinsically magnetic atoms based on their magnetic moments.
• ⚙️ The process includes reducing the cluster radius and specifying states for calculating exchange interactions.
• 📜 Three types of magnetic atoms (cobalt, cobalt 2, and iron) are considered for exchange interaction calculations.
• 🔗 The second example involves an LSDA+U calculation for nickel oxide, using different k-point meshes and Matsubara points.
• 📝 General recommendations include using multiple tails for orbitals, appropriate projections, and specific schemes for different material types.

Q & A

What is the purpose of the script 'init_jijs' mentioned in the transcript?

The 'init_jijs' script is used to automatically generate input files for calculating exchange interactions in materials, by analyzing the output file of a self-consistent calculation and identifying magnetic atoms.

What does the acronym 'DFT' stand for in the context of the script?

In the script, 'DFT' stands for Density Functional Theory, a computational quantum mechanical modelling method used in physics and chemistry to investigate the electronic structure of many-body systems.

Why is the 'simcoe' file important in generating the k-point mesh?

The 'simcoe' file contains symmetry operations that are crucial for generating the k-point mesh. By modifying this file to include only one symmetry operation (identity), the code does not read any further symmetry operations, which is necessary for creating the k-point mesh.