Dear all,
The phonon dispersion of the insulator phase for different values of the electronic smearing parameter σ, which option should be used for ISMEAR?
I noticed the Methfessel-Paxton smearing used in Phys. Rev. B 95, 245136 (2017), but I found that the official website specifically warns that this option can yield erroneous results for insulators.
Thanks a lot!
The phonon dispersion of insulator for different smearing values
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yuanchang_li
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fabien_tran1
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Re: The phonon dispersion of insulator for different smearing values
Hi,
Yes, indeed the Methfessel-Paxton method is not recommended for systems with a band gap. Thus, the choice made by Singh et al. [PRB 95, 245136 (2017)] is potentially dangerous (on the other hand, note that there is also a phase with semimetal character in their study). That means that another smearing method should be used, and according to what is mentioned at ISMEAR, this is ISMEAR=0 or ISMEAR=-5 that should preferably be used.
Yes, indeed the Methfessel-Paxton method is not recommended for systems with a band gap. Thus, the choice made by Singh et al. [PRB 95, 245136 (2017)] is potentially dangerous (on the other hand, note that there is also a phase with semimetal character in their study). That means that another smearing method should be used, and according to what is mentioned at ISMEAR, this is ISMEAR=0 or ISMEAR=-5 that should preferably be used.