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DS-AFIR issue

DS-AFIR issue
Seiji Mori July 12, 2018, 3:19 p.m. #55

 
-During a DS-AFIR calculation, AFIR program found 5 Equilibrium Structures (EQ0, EQ1, EQ2, EQ3, EQ4, where EQ4 and EQ0 are reactant and product respectively)  and 2 Transition states ,TS0 (which connects EQ0 with EQ1) and TS1 which connects EQ2 with EQ3). But, we missed  the other two TSs between EQ4- EQ3 and  between EQ2-EQ1.
 
Which option would be, in principle, more effective to find a path? To do RePATH (in the same folder where DS-AFIR was performed) or to calculate new DS-AFIRs to find the missing TSs from the each pair of EQ structures?
 
Also, another thing that caught our attention in this particular DS-AFIR output was the highlighted with a # 'hashtag' word #RIDGE-POINT (we could find this in the manual) that appears instead of "#STEP N " in the main output XXX.log . This word seems to mark the final structure in the PATH LUP   (after the structure marked with that word, the next line is this: "DS-AFIR COMPLETED, LUP-PATH OPTIMIZATION CARRIED OUT" ).  We are wondering how we  find the TS rather than the "ridge point"?
 
Thank you very much.
 
  • Re:
    Satoshi Maeda

    In general, I recommend to do RePATH in which the previous DS-AFIR results are read.

    The ridge point will be used as the TS guess only when the DS = SingleSTEP option is used. Without this option, LUP is performed after the AFIR path is obtained, and energy maxima along the final LUP path are used as the TS guesses.