Dear all,
I am doing some excitonic calculations using TDHF, and there are two parameters should be set, which are NBANDSV and NBANDSO. But I am not very clear that how to set them for different materials. How large values are recommended? Could you give me some advice?
Thanks.
Dear Jike Wang,
Thank you for your question regarding NBANDSV and NBANDSO parameters in TDHF excitonic calculations.
The optimal values depend on your accuracy requirements:
Qualitative results
The default VASP settings generally suffice, providing reasonable approximations without excessive computational costs.
High-accuracy results
Systematically increase both parameters while monitoring:
Convergence of excitation energies
Occupation of highest included bands
Computational resource constraints
Convergence testing remains essential as no universal values exist across materials systems. For critical applications, consider pushing these parameters to your hardware's memory/storage limits while verifying result stability.