[Pw_forum] How to change the weight parameter in hybrid functional?

[Marci]

Dear Myang,

Ive found an easy but dirty way that should work:
just change variable exx_fraction = 0.25_DP to whatever you want in
row no. 349 of file functionals.f90 in espresso_dir/Modules/ and do a
"make pw" (my espresso version is 4.0.3).
As you can see you need to recompile espresso each time you want to
change the mixing parameter.
A better solution would be to add a new flag to the input parameters.

Yours sincerely,

Marton Voros
--
physicist student @
Department of Atomic Physics
Budapest University of Technology and Economics (BME)
Budafoki út 8., H-1111, Budapest, Hungary
vormar_at_gmail_dot_com, vm776_at_hszk_dot_bme_dot_hu

2008/12/10 杨茂 <vcuteym at 126.com>
>
> Hi, everyone
> The "PBE hybrid functional" is given as:
> Exc(PBE)=a*Ex(HF)+(1-a)*Ex(PBE)+Ec(PBE). There is a weight parameter "a" in the range (0,1), and PBE0 is for a=0.25. How can I change the parameter "a" in the input file of PWSCF code?
> "Phys. Rev. Lett. 101, 106802 (2008)" and "Phys. Rev. Lett. 101, 046405 (2008)"
> have changed parameter "a" in order to make the bandgap value of some semiconductors agreed with experiment.
> thanks
> myang
>
> Tel:＋86-010-6275-7594
> Email: vcuteym at 126.com
> School of Physics
> Peking University
> Beijing, 100871
> China