I want to optimize the twisted-pyramidalized and ethylidene-like structure of ethene using Density functional theory (DFT) in Gaussian09. I don,t know how to optimize this kind of structure using gaussian09. Structure geometry you can see in the image that I have attached for a better understanding of structure. both structures are ethene only. This geometry (twisted-pyramidalized and ethylidene-like) of ethene is metastable and related to the excited state.
Dear Ravi Kumar,
In this tutorial, you can find an example.
http://wwwuser.gwdg.de/~ggroenh/exercise_CI/im.html
I hope it will help.
Thanks Santiago Alonso-Gil , i was trying what you have suggested and its working. I have one more question, since we know about CH2NH2 CI structure that's why you twist the structure along double bond( I think that is the case) to get fast structure fastly optimized. Is there any way to locate more accurate initial geometry for other molecule in CI ? or Is there any way to guess about geometry of molecule at CI so that we can prepare a better initial guess geometry of different molecule.
Every chemical system has a different set of degrees of freedom that are activated in a conical intersection. Having good initial guess of your different electronic configurations and performing a principal components analysis of your chemical systems should help you decide the best approach to scan the potential energy surfaces. I am not sure if I am answering your question, but, I don't know any trick that can work for every single system. Improving the basis set should help, but, it takes more time.
Santiago Alonso-Gil Is there any other free software package that do CI optimization ? Since in gaussian we can do optimization only at HF level only for CI .
- Badges
- Science topic