## Firefly and PC GAMESS-related discussion club

Learn how to ask questions correctly

** Conical Intersection Properties **
Dobromir Antonov Kalchevski

dobromirak@gmail.com

Hello,I successfully found a conical intersection with your program. Now I am trying to figure out how to characterize it - is it sloped, peaked or seamed ? What is the easiest way to find the g and h vectors, since the algorithm does not use them ? Is it possible, if the CI is practically at the peak of the ground state surface, yet not completely (let's say 10 degrees deviation from a perfect middle geometry for the ground state TS, on the reaction path coordinate (my TS is product-similar, not reagent-similar, meaning may be 20 degrees in the wrong direction)), to still go forward through the saddle point and enter the other product. Sometimes a peaked CI has more than one TS around it and more than one product, I'm just trying to figure out what is the chance that I'm getting product from the CI.

There is a $HESS group in the PUNCH file, at the end of the calculation, can I learn from it ?

Also if I try vibrational analysis, would the correct way after state averaged CI run be:

removing $mcaver $conic, and $track, along with method=conic in $statpt, and keeping the rest of the input the same, while adding the vibration specific input ?

Should I use $CONTRL NUMDER=.T. $END ?

That would keep things at nstate=2 istate=1 type of calculation, I guess.

Or can I just run a single point with the exact same input as that from the CI search at the found geometry, but also adding hssend=1 at $statpt. The CI search does switch between algorithms at some point, will the previous algorithm being active in a case like this, and change my results significantly ?

Thank you in advance, and Best regards,

Dobromir A Kalchevski

Thu Apr 16 '15 7:32pm

This message read **520** times