Debye temperature calculation formula in the QuasiharmonicDebyeApprox class

[Danil-phy-cmp-120]

Dear Friends,
Please, help me to understand the calculation of Debye temperature using debye_temperature method of QuasiharmonicDebyeApprox class.
The manual states that the formula used corresponds to Eq(6) in doi.org/10.1016/j.comphy.2003.12.001.

However, if you write down the formula from the module itself, you get:

In this expression, I don't understand where the minus sign in the degree indicators (V/n) comes from. In this case, the dimension is [K/m]. Could you please point out the error?

[janosh]

i assume you mean

pymatgen/pymatgen/analysis/quasiharmonic.py

Line 239 in fe4c7c8

debye = 2.9772e-11 * (volume / self.natoms) ** (-1.0 / 6.0) * f * np.sqrt(self.bulk_modulus / self.avg_mass)

not too familiar with this part of pymatgen myself but it could be a bug. maybe @JaGeo knows more?

[janosh]

this reads LLM generated. if so, would be good to preface with some context on what model and prompt was used. otherwise it's easy to mislead people

[hongyi-zhao]

@janosh I’ve deleted all the non-precise non-human strictly reviewed content. See here for the related discussion.