Transition sate search

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Some general ideas about TS searches

1. It is very important to start the search from a point in the close proximity of the TS geometry.
2. There is a discussion in the forum on strategies for finding a good starting point for TS searches.
3. remember to read in or calculate the analytical Hessian for the start structure of the TS search

 
%mem=720MB
%chk=tsOpt_2.chk
#p opt=(ts,rcfc,noeigentest,modredundant,maxcycle=50)
guess=read freq=internalmodes b3lyp/6-31g(d) nosymm 5d

ts optimisation

0 1
 B                      -1.236584    0.378750   -0.110055
 C                      -2.405521    0.181389   -1.187202
 C                      -4.347179   -0.297143   -3.192147
 C                      -3.533357   -0.627119   -0.946993
 C                      -2.286814    0.744689   -2.471355
 C                      -3.238203    0.513393   -3.462119
 C                      -4.498930   -0.866161   -1.927766
 H                      -3.711589   -1.033054    0.049952
 H                      -1.422336    1.366096   -2.687732
 H                      -3.121640    0.954559   -4.448063
 H                      -5.363572   -1.484551   -1.712026
 Zn                     -1.566231   -2.368610   -0.002221
 C                      -2.339741    1.315183    1.486777
 H                      -3.256031    1.888895    1.292787
 H                      -2.654898    0.275728    1.589159
 C                      -2.174919   -4.143079   -0.365984
 H                      -3.078791   -4.377096    0.207316
 H                      -1.416062   -4.889148   -0.107127
 H                      -1.995382    1.574765    2.503551
 H                      -2.413758   -4.260128   -1.428236
 Zn                     -0.927697    2.617922    0.654988
 Zn                      1.157009   -0.088897    0.108494
 O                      -0.125127    1.206992   -0.453282
 C                       2.918139   -0.837669    0.344392
 H                       3.141574   -1.586433   -0.424609
 H                       3.695462   -0.068277    0.285597
 H                       3.011362   -1.328681    1.319685
 C                      -0.496733    4.502081    0.853081
 H                      -1.143223    5.116451    0.214810
 H                      -0.627046    4.854052    1.882762
 H                       0.539876    4.706700    0.561364
 O                      -0.740993   -0.833906    0.496685
 C                      -5.370656   -0.516170   -4.272789
 F                      -6.014288    0.631740   -4.587131
 F                      -6.310418   -1.417804   -3.915829
 F                      -4.796540   -0.960678   -5.414787

1 13 B

Comments to the input example

1. The option "noeigentest" prevents the calculation from stopping if the number of imaginary frequencies is different from 1
2. the option "modredundant" can be useful to make sure that the coordinate important for the reaction is defined in the list of redundant coordinates. In the example above the bond distance between atom 1 and 13 is added to the list