I am doing ORCA calculation for my high spin Iron(III) complexes to calculate ground state geometry and TDDFT. few of them calculated successfully. but one of my complexes having 340 atoms including one Fe and other C,H,N,O which running more than 20 days and still it is running for ground state optimization.

I expecting some suggestions to reduce the time of the calculation or calculation setup details for this kind of larger molecules.

for the ref, pls find the input date which i am using right now,

! B3LYP OPT def2-SVP def2/J NormalPrint Grid4 RijCosX GridX4 TightSCF

%basis

NewGTO 26 "def2-TZVP" end

NewAuxGTO 26 "def2/J" end

end

%scf

MaxIter 500

CNVDIIS 1

CNVSOSCF 1

end

%output

print[p_mos] true

print[p_basis] 5

end

* xyz -3 6

coordinates

*