Questions related to abstract one-dimensional coordinates which represent progress along a reaction pathway.

learn more… | top users | synonyms

7
votes
1answer
94 views

Ballistic behavior of molecules on potential energy surfaces

I came across the following sentence in a publication$^1$: "At this point we have to remember that the computed MEP path [sic] represents the reaction in the absence of any kinetic energy, while in ...
5
votes
3answers
202 views

Intrinsic Reaction Coordinate calculation— both sides of TS lead to same minimum

I am currently trying to find an addition transition state and verify it using an IRC calculation. I have found a good candidate, but the IRC calculation gives the same minimum on each side of the ...
2
votes
0answers
227 views

Are multiple transition states possible? Criteria to choose the correct one?

I am studying a reaction using electronic structure methods using various software packages (ORCA,GAMESS, G09) and have found two possible transition structures between product and reactant. Both have ...
5
votes
2answers
771 views

Reaction Pathways: What to do when IRC geometries are relaxed (optimized) and the energy changes significantly

The Story: Reaction pathways can be difficult things to deal with using electronic structure methods. Intrinsic reaction coordinates (IRCs) can be determined a number of ways (a discussion of these ...
2
votes
1answer
44 views

How to trace an Energy Time diagram?

I'm looking for data to create a simple graph of an exothermic or endothermic reaction but can't find any. Could someone help me with some enough data to create a Energy(time) simple graph.
2
votes
1answer
480 views

Intrinsic Reaction Coordinate - What does 'Connectivity' really mean?

I am currently in the process of connecting transition state (TS) structures to other minima in order to determine a reaction pathway. Now I understand the basic concepts of this method. You start ...
4
votes
2answers
119 views

What is the energy package released to the outside world?

Consider a chemical reaction where two different particles form another one $$\ce{O + O_2 -> O_3}$$ I find it confusing how this can be an exothermic process. How to picture the release of $+\...
16
votes
1answer
2k views

What does “reaction coordinate” mean? What does it mean when a reaction has TWO reaction coordinates?

I'm familiar with the concept of a reaction coordinate from high school chemistry as some generic conformational parameter that all of the intermediate states of a chemical reaction lie upon. Recently,...