Ll4915
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- What value does the total gradient of the potential energy surface have at a minimum and at a transition structure? Briefly explain how minima and transition structures can be distinguished using the curvature of the potential energy surface.
- The total gradient of the potential energy surface is zero at a minimum and at a transition structure. According to the definition: transition state is the maximum on the minimum energy path, the transition state in unstable equilibrium, thus the second derivative of potential energy against bond distance is smaller than zero. Whereas the minima of potential energy surface is in stable equilibrium, the second derivative of potential energy against bond distance is larger than zero.
- Best transition state position (rts)
- As explained previously at transition state, the total gradient of the potential energy surface is zero. By plotting a surface plot with r1(0)=r2(1)=0.74 A (bond length of H-H bond), the maximum of minimum energy path gives the transition state distance: 0.91 A. Internuclear Distance vs. time plot showed AC distance approximate to 1.8 A twice the BC bond distance Thus the bond distance between AB and BC dose not change. The system is in a transition state.
- Comment on how the mep and the trajectory you just calculated differ.