Firefly and PC GAMESS-related discussion club


 
Learn how to ask questions correctly  
 
 
We are NATO-free zone
 



Re^4: SCF Convergence Problem in modelling Ag cluster

John McKelvey
jmmckel@gmail.com


A long time ago while at Kodak [better then than now :-( ] using deMon and ECP relativistic basis functions for Ag with about 17 ( I don't remember exactly) valence electrons and smearing about the band gap things went smoothly.

Best regards..

John McKelvey

On Fri Nov 4 '11 2:04pm, Davide Vanossi wrote
---------------------------------------------
>Dear Amir,
>         I’m absolutely agree with you and, in fact,  I tried the lanl2dz from the beginning; unfortunately this introduced, on my system, a quasi linear dependence on the basis set which is not a good companion “to cure” the SCF convergence problem. For the moment I have “solved” the problem using another quantum chemistry package (NWChem) which permits to obtain a feasible SCF convergence even for the singlet multiplicity case.
>Thank you very much for your interest.
>Have a nice day.

>    Davide
>
>
>On Fri Oct 28 '11 11:56am, Amir Nasser Shamkhali wrote
>------------------------------------------------------
>>Dear Davide
>>I think that relativistic effects can be important for Ag atom. So, it's better to perform calculations with an ECP basis set which has been included relativistic effects (spin-orbit coupling) such as LANL2DZ and etc. Also these basis sets reduces the cpu time and memory considerably. You can download them form this site:
>>https://bse.pnl.gov/bse/portal
>>Please note that spin-orbit coupling reduces spin multiplicity and do not use high spin cases. The 2S+1=3 or 5 or 7 is sufficient.

>>Best wishes


[ Previous ] [ Next ] [ Index ]           Sat Nov 5 '11 1:43pm
[ Reply ] [ Edit ] [ Delete ]           This message read 629 times