How to check that the TS structure is the right one

· It is possible that the TS structure found by a geometry optimization is the TS for a process other than the one of interest.

· To check that the TS structure really is the desired TS, examining the atomic displacements for the reaction coordinate can show which atoms are involved.

· To prove that it really is the TS, the calculating the steepest descents path from the TS should produce (in one direction) the reactants and (and in the other direction) the products.

· This path calculated in mass-weighted coordinates from the TS is called the intrinsic reaction coordinate.

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