I have been posting unanswered questions about LAMMPS here: https://www.facebook.com/groups/lammps,
about Quantum ESPRESSO here: https://www.facebook.com/groups/Quantum.Espresso,
about VASP here: https://www.facebook.com/groups/Vasp.Code,
about ABINIT here: https://www.facebook.com/groups/AbinitCode,
and while it's not been necessary yet, I know that I can post questions about CASTEP here: https://www.facebook.com/groups/142037023098692,
and about Wien2k here: https://www.facebook.com/groups/wien2k.Algeria/, and here: https://www.facebook.com/groups/434787909952863/.
However I came across this unanswered CP2K question: Reading in E-field with CP2K and couldn't find an analogous place to post it, other than perhaps CP2K's own forum or mailing list, which I've never used, so I'm not comfortable enough with the culture of what might be appropriate to post there.
Where else can we post unanswered questions apart from the places already mentioned before (Psi-K forum, CCL, Molecular Dynamics News, and the above groups)?