#1 Fri Jun 29, 2018 2:53 pm
Registered: Jun 2018
I am trying to calculate the X-ray absorption spectra using the Real Time Time Dependet-DFT (Real time TDDFT) in the new Qchem version 5.0. I followed the instructions of the manual " url=http://www.q-chem.com/qchem-website/manual/qchem50_manual/sec-RT-TDDFT.html" , but i don't get any spectra at all.
Basically, a plot the sum of the imaginary parts of the Fourier transform of the dipole moment against the time:
plot(w, w*sum(Im[a(x)] + Im[a(y)] + Im[a(z)])
... but I got a trend which doesn't look like a spectra, becasue it has still negative values.
then the spectra is
A = (s(xx) + s(yy) +s (zz) )/3
k= kick direction, x,y, or z
s= cross section
A= absorption spectra
Does anybody have any idea hot to get spectra with real time TDDFT?
Any help would be more than appreciated.