Dear friend Ijaz Shahid

I created a video to explain

https://youtu.be/hy_Keyx3FA4?si=2AJ56aao0cwIremd

I appreciate your dedication to addressing the persistent issue of imaginary phonon modes in your computational material science work. As you noted, distinguishing between genuine dynamical instabilities and numerical artifacts is crucial, especially under the challenging conditions of high pressure and stringent convergence.

Given your careful attention to convergence parameters, it may be worthwhile to further experiment with the k-point grid density or to increase the supercell size beyond the current 3 × 3 × 3 configuration. These adjustments can sometimes reveal whether the imaginary modes are artifacts of finite-size effects or boundary conditions. Additionally, testing alternative boundary conditions could provide further clarity on the stability of your system.

It is also important to consider the influence of numerical precision and pseudopotential selection. Exploring different pseudopotentials or adjusting cutoff values might help eliminate spurious modes. If feasible, cross-validating your results with alternative computational tools or methodologies could offer additional confidence in your findings.

Finally, if experimental data under similar conditions are available, comparing your computational results could provide valuable validation.

Please let me know if you would like to discuss any of these suggestions further or if you are interested in a collaborative troubleshooting session. I look forward to hearing your thoughts.

Best regards,

Kaushik