CASTEP transition-state searches are performed using synchronous transit methods. These work best in situations where the structures of the reactants and products are known, but the location of the transition state is not.
A transition-state search requires a trajectory document (for example, an
.xtd file) as input. The reactants are
taken from the first frame of the trajectory, and the products from the last frame. For quadratic synchronous transit (QST) calculations, the
current frame is used for the QST mid-point. The trajectory files generated by any of the other transition state search methods may be
used as input to a QST run.
When a transition state search is performed on a periodic system the unit cell is fixed.
For a detailed description of the quality settings please refer to the Setting the quality of a calculation topic.
Synchronous transit calculations are performed in Cartesian coordinates. There is no option to override this.
To set up a synchronous transit calculation
To optimize the reactant and product structures as part of the TS Search run, check the Optimize reactants and products checkbox on the CASTEP Transition State Search dialog.
Synchronous transit methods
Finding equivalent atoms
Previewing reaction pathways
CASTEP Transition State Search task
CASTEP Transition State Search dialog