Finding linearisation energies for SrRuO3

[Thomas Durrant]

Hi people, thanks for the help with my previous problem. I've been trying a more complex crystal, but I haven't got very far. I've been attempting SrRuO3, but I get the following warnings:

Warning(occupy): minimum eigenvalue less than minimum linearisation energy : -111.9643717 -2.804800000
for s.c. loop 1

Warning(linengy): could not find 5 linearisation energies in s.c. loop 2

I assume this is happening because my muffin tins are too close together, as I also get the following message.

Info(checkmt): reduced muffin-tin radius of species 2 (Ru) from 2.6000 to 2.1823
Info(checkmt): reduced muffin-tin radius of species 3 (O) from 1.8000 to 1.5108

How should I work around this problem? I have played around with the parameters I understand, but none of them have helped get the minimum eigenvalue above the minimum linearisation energy. In paticular, using autormt did not seem to help.

Thanks for any suggestions, I have also attached my ELK input file.

[supermarche]

Dear Thomas,

a few things I recognized are not optimal in your setup: you chose autokpt=.true. and ngridk at the same time. Ngridk will be ingnored in this case. Depending on the elk version (ver. > 2.1.22) you are using, nempty 40 is pretty large. Should be between 2 and 10 in the usual case. What is the reason to choose a spin-polarized core? (spincore = .true.)

If you don't get rid of the minimum linearization warning, try to adjust the radii of Ru and O beforehand in the species file, i.e. reduce Ru to 2.3, and leave O as it is. Nevertheless, an oxygen radii of 1.5 bohr is not severely critical. I have calculations with smaller sphere radii of oxygen. Perhaps rgkmax, gmaxvr etc. (parameters for the basis set expansion in the interstitial region) are too small for this sphere setup.

All the best,
Marc