The double-ended-ADDF (d-ADDF) guided TS search is performed. For its introduction, see Double-ended minimum search by SCW. The two input structures are assumed to be connected by a TS.
An input file for formaldehyde is:
# 2PSHS/MP2/6-31G
0 1
C -0.000000000000 -0.000000000000 -0.549482561269
O 0.000000000000 0.000000000000 0.708343639882
H 0.000000000000 0.934113144104 -1.131025039307
H -0.000000000000 -0.934113144104 -1.131025039307
Reactant
C -0.000000015446 -0.086358195130 -0.690448195581
O 0.000000011426 0.076071515927 0.664179018327
H -0.000000000148 1.026444496589 0.907185708275
H 0.000000002804 -1.202120254263 -0.788241668362
Here, the upper structure is a product and the lower structure is a reactant. The product structure should be an (tightly) optimized equilibrium structure. The optimized structure will be printed at the bottom of xxx.log file as:
Optimized structure, SYMMETRY = Cs
C 0.000000000892 -0.058770853991 -0.660974969317
O -0.000000000202 0.048859121960 0.712568337957
H -0.000000003655 1.042149614084 0.087202994076
H -0.000000003661 -1.109768350045 -1.021866451062
ENERGY = -113.869691999440
S**2(SCF) = 0.000000000000