[Mesa-users] Problems converging low mass stars because of min_timestep_limit

[Inma Moyano]

Dear MESA Users,

My name is Inma, a master's student. I am using MESA's version 23.05.1 on
Ubuntu 23.10.

I am working on models for low mass stars (0.1, 0.35 and 0.6 Msun), testing
different sets of opacity tables for low temperatures (kap_lowT_prefix
= 'lowT_fa05_a09'
, 'lowT_Freedman11') and also experimenting with the nuclear reaction
networks (options 'basic.net', 'h_burn.net' and 'mesa_49.net').

I had no issues using the net 'basic.net', but when I use 'h_burn.net' and '
mesa_49.net' some models of 0.35 and 0.6 Msun do not converge due to the
following error:

                                                     dt
 6.9699513407705602D-09
                                     min_timestep_limit
 1.0000000000000000D-08
 stopping because of problems dt < min_timestep_limit
terminated evolution: cannot find acceptable model
termination code: min_timestep_limit

None of my 0.35Msun models converge using any of the two nets or opacities.
WIth regard to 0.6Msun models, they only converge using 'lowT_fa05_a09'
opacity, for both nets, but when I change the opacity to Freedman11 they
don't anymore.
Has anyone had this problem before or knows why this is happening? Here I
attach my inlist_project file and also the net files.

Best regards,
Inma
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