IRC Reaction: Cyclobutene Ring-Opening to form Butadiene (Home)

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  ===>    In this simulation, cyclobutene ring-opens to form 1,3-butadiene. The step-size used is 0.1mass-weighted Angstroms. In an IRC, the concept of time is missing: At each point on the reaction, all kinetic energy is annihilated, so the atoms move only in response to the forces acting upon them.  There are three stationary points on the reaction surface, points where all forces are zero, these are the reactant(s), the transition state, and the products.  For this reaction, the transition state occurs when the CH2-CH2 distance is 2.1 Angstroms.

For reference: 

 DHf(cyclobutene) = 37.5 kcal/mol
 DHf1,3-butadiene = 26.0 kcal/mol

Data set used by MOPAC:

 irc=-1* x-priority=0.1 gnorm=0.1
 Cyclobutene -> butadiene

  C         0.00000000 +0    0.0000000 +0    0.0000000 +0                     -0.2711
  C         2.09542702 +1    0.0000000 +0    0.0000000 +0                     -0.2711
  C         1.41235903 +1   74.6911459 +1    0.0000000 +0    2    1    0      -0.1643
  C         1.39536653 +1  102.9147444 +1   14.9750623 +1    3    2    1      -0.1645
  H         1.07961066 +1  121.5806832 +1  141.5488537 +1    1    4    3       0.1329
  H         1.08188876 +1  122.7322763 +1  -58.8561305 +1    1    4    3       0.1527
  H         1.07962359 +1  121.5787713 +1  141.5886061 +1    2    3    4       0.1329
  H         1.08192201 +1  122.7666089 +1  -58.7492900 +1    2    3    4       0.1527
  H         1.07183872 +1  129.4772894 +1  150.2423278 +1    3    4    1       0.1498
  H         1.07184180 +1  129.4782103 +1  150.2141939 +1    4    3    2       0.1498