In a Linear Transit (LT) run you define a number of atomic coordinates (at least one) to be the LT parameters: these get an initial and a final value. The LT is defined as the simultaneous linear change of these parameters from their initial to their final values. This is carried out in a number of equidistant steps. In a non-linear transit calculation these may be not equidistant steps. The total number of LT points is specified on input. At each LT point the remaining atomic coordinates - those that are not LT parameters - may or may not be optimized: the (final) structure and energy at each LT point are computed. A Linear Transit (LT) run is therefore just a sequence of (related) constrained Geometry Optimizations.
The LT scan may be used for instance to sketch an approximate path over the transition states between reactants and products. From this a reasonable guess for the Transition State can be obtained which may serve as starting point for a true transition state search for instance.
Whenever a geometry subkey is applicable in a Geometry Optimization, it will apply in a Linear Transit run in each of the optimizations that are carried out at the distinct Linear Transit points, and the same default values apply.
Linear Transit (new branch)
