How to select Restricted, Unrestricted and open shell in gaussian calculation ? what is it mean? and how to calculate it or select it in our case ?
Dear Paras,
what system do you wish to consider? And what approach do you want to use for it? In the case of Hartree-Fock approach, you can use the following keywords:
HF - for Restricted close-shell system (all orbitals are considered as doubly occupied);
ROHF - for Restricted Open Shell system;
UHF - for Unrestricted approach (all alpha- and beta-electrons are treated separately, and alpha- and beta orbitals are considered as singly occupied).
The table in the file attached illustrates all these concepts really nice:
http://www.tau.ac.il/~ephraim/RHF.pdf
Best regards,
Aleksey.
Dear Paras,
what system do you wish to consider? And what approach do you want to use for it? In the case of Hartree-Fock approach, you can use the following keywords:
HF - for Restricted close-shell system (all orbitals are considered as doubly occupied);
ROHF - for Restricted Open Shell system;
UHF - for Unrestricted approach (all alpha- and beta-electrons are treated separately, and alpha- and beta orbitals are considered as singly occupied).
The table in the file attached illustrates all these concepts really nice:
http://www.tau.ac.il/~ephraim/RHF.pdf
Best regards,
Aleksey.
- Badges
- Science topic