Steven's operators acting on L: Interpretation of parameters

[christiansen]

Dear Easyspin comminity

I have recently started working with actinide ions, and have therefore started building Hamiltonians directly from the L and S quantum numbers. In this case, the crystal field (CF), in the form of Steven's operators, act on L rather than S. Thus, Easyspin now parametrises the CF using CF_k^q constants instead of B_k^q that is normally used when Steven's operators act on S.

Is there any way to translate the CF_k^q to the B_k^q formalism to better compare with literature values for CF parameters?

Assuming that Easyspin uses Wybourne notation for Sys.CF, I tried using table A1 in this paper https://www.sciencedirect.com/science/a ... 492X#s0125 to translate reported Bk_q constants in a Steven's operator formalism to use with Easyspin. Unfortunately, my calculation using the reported parameters is still different than the results reported.

Best,
Rasmus

[Stefan Stoll]

The matrices for the CF parameters Sys.CF1 etc. are implemented in the EasySpin function ham_cf.m. Have a look at the source code of this function here. It looks like these are just Stevens operators, since ham_cf calls stev.