I have asked on Castep forum but I think this forum is more appropriate:

I want to optimize supercell with adsorbed molecules on it and calculate band, DOS structure and IR spectra. I mastered making a supercell with vacuum above and put several molecules "adsorbed", but when I select Polarizability and IR I get following message.

My questions are:

1. if I have alkali and Earth alkali metals I still can't calculate IR spectra for any of the system, so Castep can't calculate IR for anything with metal ions?
2. crystal is semiconductor. should I still fix occupancies?
3. this system has no metal atoms yet. others will have

thanks

Jonas

CASTEP does not yet support the current settings for linear response calculations.

To perform a phonons or polarizability calculation:

Please choose a norm-conserving, not ultrasoft, pseudopotential for element H

Please choose a norm-conserving, not ultrasoft, pseudopotential for element N

Please choose a norm-conserving, not ultrasoft, pseudopotential for element O

Please choose a norm-conserving, not ultrasoft, pseudopotential for element Si

Please choose a norm-conserving, not ultrasoft, pseudopotential for element S

Linear response calculations for metals are not yet supported. If the current system is an insulator,

please fix the orbital occupancy on the SCF tab of the Electronic Options dialog.