# CCL: SOC calculations

*From*: Spyroulla Mavrommati
<mavrommati.spyroula(~)ucy.ac.cy>
*Subject*: CCL: SOC calculations
*Date*: Tue, 5 May 2020 09:24:16 +0000

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