Non-zero value for Bz and psiList[1]
asked by Saki IMADA (2024/06/04 02:17)
Hello, I have two questions.
I edit the input files for NiO in the crystal field approximation to fit my materials. I acquire spectra under a non-magnetic field.
Question 1: I think the reason for setting Bz as a non-zero small value is sorting the initial Hamiltonian from the lowest to the highest Sz values. Do I understand it correctly?
Question 2: When I use “psiList” in the spectra calculation lines, I get the same number of spectra (for Npsi=3, I get 3 spectra). When I use “psiList[1]”, I get only one spectrum for the state with the lowest Sz value irrespective of Npsi values in case I set Bz as a non-zero small value. Do you recommend to use psiList, not psiList[1]? (I'd like to understand the reason for “psiList” in XAS/FY and “psiList[1]” in RIXS spectra calculation lines (CreateYield/Resonant lines).)
Best regards,
Saki
Answers
I'm not following quanty projet enymore
Dear Saki,
(1) Indeed I often include a small magnetic field to lift degeneracies and order the states in the output.
(2) In general calculations with Npsi=1 are faster than calculations with Npsi=3. For XAS and FY the calculations are very fast any how, for RIXS speed can be an issue.
If you do the measurements at very low temperatures only the lowest state is occupied. In this case you can set Npsi=1. Or do an eigenstate calculation for the lowest 3 states, but only include the lowest state when calculating spectra. At higher temperatures also the excited states get occupied (via Boltzmann statistics) and you thus need to include them in the calculation.
Best wishes, Maurits