CCL: SOC calculations

 Sent to CCL by: Spyroulla Mavrommati [mavrommati.spyroula ~~ ucy.ac.cy]
 Dear Seyhan,
                       an easy way to compute spin-orbit coupling (SOC) between
 excited singlet and excited triplet states in ADF, is to include the SOC as a
 perturbation to the scalar relativistic calculation of the excitation energies.
 In the input file you should specify:
 RELATIVISTIC SCALAR ZORA
 EXCITATIONS
    lowest n
 END
 SOPERT
 PRINT SOMATRIX
 n is the number of excited states to include in the computation and the keyword
 "PRINT SOMATRIX" implies that the SOC matrix will be printed in the
 output. Since the SOC matrix is written in the basis of the singlet and triplet
 excited states, you can extract the couplings between them.
 Further clarifications are available in the manual (section 6.3.6: Excitation
 energies and Spin-Orbit coupling) and on the website (https://www.scm.com/doc/ADF/Input/Excitation_energies.html?highlight=somatrix?highlight=EXCITATION+ENERGIES).
 Please, read them carefully, they are very helpful.
 Have a nice day,
 Spyroulla
 Sent to CCL by: "Seyhan  Salman" [ssalman.:.cau.edu] Hi all, How do
 you calculate Spin-orbit-coupling between the excited singlet (S1) and triplet
 (T1) states using ZORA and ADF program?
 Thank you.
 Seyhan