Author Topic: Strange excitations while using desy  (Read 1666 times)

Kwiatkowski

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Strange excitations while using desy
« on: September 17, 2014, 01:42:54 pm »
I'm working on determination of the plasmon excitations of spheres of different sizes.

I did the calculations for it using desy getting either the symmetry oh or d4h.
The excitations of all but one symmetry groups had a oscillator strength of 0.0 and the rotatory strength was 0.0 far all excitations.

If I used the symmetry group c1 all excitation had non-zero oscillator and rotatory strengths (with a great variance of values) and the resulting excitations were different from before.

Does anyone know, why the results differ that way?

christof.haettig

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Re: Strange excitations while using desy
« Reply #1 on: October 01, 2015, 10:34:26 am »
maybe a matter of convergence thresholds.
If you run in C1 selection rules will only be fulfilled within numerical convergence of the structure, orbitals and densities. Large systems require often tighter thresholds.