[Wien] Effective Mass

[Oleg Rubel]

Dear Pablo,

It seems that the error message points to the source of the problem 😉
The file with momentum matrix elements ` GaAs1.mommat2up` is empty (0 lines). I would check which files are created/modified as the result of ` x optic -so -up`.

Best regards,
Oleg

> -----Original Message-----
> From: Wien <wien-bounces at zeus.theochem.tuwien.ac.at> On Behalf Of
> delamora
> Sent: Tuesday, July 28, 2026 6:30 PM
> To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
> Subject: [Wien] Effective Mass
> 
>   Caution: External email.
> Dear WIEN2k community,
> 
> I am trying to calculate the "Effective Mass"
> I am doing the example "GaAs" that is in the article;
> 
> Perturbation approach to ab initio effective mass calculations Computer
> Physics Communications 261 (2021) 107648
> 
> In section "2.3. Sample work flow"
> 
> After doing the GaAs.struct file I do the following instructions; init_lapw -b -vxc
> 13 -rkmax 7 -numk 500 run_lapw -ec 0.00001 -cc 0.0001 save_lapw -d
> noSOC init_so_lapw run_lapw -ec 0.00001 -cc 0.0001 -so x lapw1 x lapwso ln
> -sf GaAs1.vsp GaAs1.vspup ln -sf GaAs1.vsp GaAs1.vspdn ln -s case.vectorso
> case.vectorsoup cp /home/Programas/WIEN2k/SRC_templates/case.inop
> GaAs1.inop x optic -so -up
> 
> x mstar -up -settol 0.00001
> 
> 
> *** Here I get an error;
>  Detected input arguments = 2
>  Input mommat file = ./GaAs1.mommat2up
>  Degeneracy tolerance dEtol = 0.00001 [Ha]  Confirming text-to-number
> conversion dEtol =  1.00000E-05 [Ha]  The input file ./GaAs1.mommat2up
> was found.
>   number of lines in mommat file = 0
>  The file ./GaAs1.mommat2up is too short and most likely useless. Stopping
> 0.003u 0.008s 0:00.01 0.0%    0+0k 0+0io 0pf+0w
> 
> Saludos
> 
> Pablo