Hello everyone
I have successfully drawn CuO structure in Gauss view through PBC, I need to know what are the appropriate parameters in functional and basis set in order to successfully optimize the crystalline structure. Please refer to some literature, websites and forums regarding this
thank you
There is no unified "appropriate" functional and basis set, many people prefer different stuff. However, it makes sense to climb the Jacob's ladder of functionals with your optimization: Article Jacob's Ladder of Density Functional Approximations for the ...
That means, first you optimize your structure with a simple GGA functional (BP86 is popular for that), then you can go to more sophisticated simulations (e.g. a hybrid like B3LYP/PBE or a meta-GGA like TPSS). Concerning the basis set: its size should be increased along with the functional quality. It is not really helpful to blast BP86 with a large basis such as 6-311+G or def2-qzvp, for the preoptimization 6-31G or def2-svp will suffice while for the better functionals you should also consider using those larger basis sets. By the way, if you go to more complicated (=less symmetrical) structures, you might consider preoptimizing you structure with a semiempirical method such as PM7, that accelerates your process a lot.
Good morning everybody
I have a problem in modeling inorganinc structure with Gausssain 09, the optimisation steep does not converge, an message of error termination appears in the out put file, I do not inderstand the problem
in the attached file an exemple of a calculation of inorganic structure that does not converge, please anyone can give me any explication and a help
Thanks and best regards
M.Chemek
People uses different basis sets bu the most common is B3LYP /6-311G**dp. Try using this, it takes less time .
https://barrett-group.mcgill.ca/tutorials/Gaussian%20tutorial.pdf
- Badges
- Science topic