Reference energy while plotting the excitation energy

[Kamal Dhungana]

Dear PYXAID users,

How can we find the reference energy while plotting the time evolution of the average excitation energy ( http://pubs.rsc.org/en/content/articlelanding/2016/cp/c5cp06603d#!divAbstract, Figure 2) in pyxaid? If I consider the HOMO to LUMO excitation energy as the reference energy,  I found the final energy (after subtracting the reference energy) negative.   I have attached time evolution of HOMO-LUMO excitation energy here (test.pdf). At t=0, the energy is 2.76 eV. If I subtract this energy (2.76 eV), then I'll get negative energies at several other points because this energy is not the least one.  Could someone please give me some suggestions on this?

Best Regards,

Kamal

[Alexey Akimov]

Kamal,

If you take the HOMO->LUMO as the reference energy, then you should not allow the electron to go below LUMO (exclude the "GS"). Then the energies will be non-negative.

Best,

Alexey

[Kamal Dhungana]

Dear Prof. Alexy, 

I performed test calculations with and without ground state ("GS") to compare the time evolution of the average excitation energies. Energy evolutions in these two cases are very different. I have attached these two graph here (Excluding_GS.pdf and with_GS.pdf). To exclude the "GS", I modified the input script as:

params["states"] = []

#params["states"].append(GS)

for se in SE:

    params["states"].append(se)

My interest here is to plot the time evolution of the average excitation energies as in Figure 2 in Phys. Chem. Chem. Phys.18, 5219 (2016) (http://pubs.rsc.org/en/content/articlelanding/2016/cp/c5cp06603d#!divAbstract). Any suggestions would be highly appreciated.

 

Best Regards,

Kamal Phys.Chem.Chem.Phys.,

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