Maybe you can try The ADF Program

If you are using Gaussian, you can use CASSCF=SpinOrbit keyword to calculate spin-orbit coupling between two spin states. For details: http://www.gaussian.com/g_tech/g_ur/k_casscf.htm

Thank you sir...

Maybe you can try The ADF Program

plenty of programs do SO corrections. i used Orca's MRCI program and it works fine and fairly easy to use, see the example input below.

1. you need to specific a "block" or multiple blocks with certain multiplicity or multiplicities, for ground state Br atom it is 2 (hence: NewBlock 2 *, also in xyz 0 2, which is similar to G09 input).

2. you then need to define the active space as with all other CAS-type calculations, basically counting the "important" electrons and orbitals (e.g., CAS(5,3) for the 5 p-electrons and 3 p-orbitals of Br).

3. lastly you should specify how many states you want for obtaining the SO term, i use 5 (Nroots 5) here for Br, which is probably already overkill but again it depends on your specific system.

-----------------------

! ROHF def2-SVP

%MRCI

NewBlock 2 *

Refs

CAS(5,3)

End

Nroots 5

End

SOC

DoSOC True

End

End

* xyz 0 2

Br 0.0 0.0 0.0

*

Thank you for your answers. I can try ORCA but not for the ADF because we don't have that.

You can get trial version of ADF, Francis. As far as I remember, it's free for 1 month, or even two. To me ADF (with ZORA program in it) is the best for calculating relativistic effects.

You can also calculate spin-orbit coupling with Molpro, see https://www.molpro.net/info/2012.1/doc/quickstart/node32.html

Dear Francis, I have your problem too. I want to know How we can calculate the spin-orbit coupling?is the Gaussian package suitable and does it give reliable outputs?

Francis any information which you have found on this topic would be regarded.

Dear Olga Dmitrenko,

I have run the job on ADF for SOC and got normal termination but couldn't able to find the Hos in cm-1. Please help me in this regard.

Thanks

Hussain

Dear Manzoor Hussain,

I don't remember that I had problems with units, as far as I understand, you can convert them by yourself. What I've got from my calculations (about 10 years ago, I think) were NMR Shieldings in ppm. I totally forgot details on that project, but I am sure it is possible to figure out. Usually I take some nicely done paper on similar study and try to repeat by myself one calculation. Google my publications with Dybowski, C. and see what was done.

@Respected Olga Dmitrenko,

Thanks a lot. I will follow your paper. I just need to see the procedure because this is the first time to calculate SOC. Therefore feel problem to use the concerned data from the out file.

Once again thank you for your quick reply.