Fractional occupation


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Just Got Here
Hello,

I am new to nwchem and want to calculate the energy of a single C-atom in a closed shell dft calculation with fractional occupation of each of the three 2p orbitals with a value of 0.66666666.

I tried to achieve this by smearing, but for every value I choose in the smearing Gaussian I achieved a different result (and even much lower energies could be achieved what I actually don't understand). I also tried with the rabuck option, but the calculation was not converging. What is the right way do do this ?

My input file is

title "C_pv3z"
geometry units au
C      0.0 0.0 0.0
end
basis
C library aug-cc-pvtz 
end
dft
grid xfine
smear 0.001
xc slater perdew81
iterations 150
# convergence rabuck 30
end
TASK DFT

Thanks for your answers

Volker