Opacity partial deriv. definition

[pjuelsgaard]

Hi.
tl;dr: How are the opacity derivatives kap_T and kap_rho defined?
I have issues with a model and the amplitude of the opacity derivatives, with the shape of the slope being more or less correct, when compared to a similar model computed with MESA, but the amplitudes are vastly different (For kap_T, mine are ~[-4 - 10], MESA is around [-3000 - 2000], in case of further inquiry I can attach pictures).
The model I have contains (dlnkap/dlnP)_T,mu , and (dlnkap/dlnT)_P,mu.
I convert to the values I believe GYRE uses via.
(dlnkap/dlnrho)_T,mu = alpha^-1 * (dlnkap/dlnP)_T,mu
(dlnkap/dlnT)_rho,mu = (dlnkap/dlnT)_P,mu + delta/alpha * (dlnkap/dlnP)_T,mu

I suspect I might be missing something from the transformation, but I do not know what I would be

Kind regards
- Peter

[rhtownsend]

Hi Peter --

The opacity partials given by MESA are typically defined as dkappa/dlnT etc, whereas GYRE uses dlnkappa/dlnT. Does that explain the difference?

cheers,

Rich

[pjuelsgaard]

Thanks a lot.
Now my models make a lot more sense