Hi,

I am trying to relax a 64 atom supercell of CdMnTe using ionmov 2 and optcell 2.

When dealing with bulk CdTe, the SCF loop converges and the structure relaxes below my tolerance (10e-4 tolmxf) after a few Broyden iterations - all good!

However, once I introduce Mn to the supercell (e.g. Cd0.5Mn0.5Te) the SCF loop does not converge but noticeably also starts at a very high density residual (nres2=2.060E+02) which does not improve after 30 SCF iterations (nres2=7.362E+02). After a few Broyden interations of the SCF loop not finding convergence, the calculation then crashes.

Any suggestions as to why this is happening and what steps/parameters I can change to get the SCF convergence to work would be greatly appreciated. I have played around with changing diemac (8, 12, 50) but this has not helped.

I have attached my input file for the CdMnTe supercell calculation and the corresponding output file.

den.in (5.75 KB)

den_oc2im2_d50.out (74.4 KB)

Cheers,

kalkm1