Bond dissociation curves

If we were to calculate the potential energy V of the diatomic molecule AB as a function of the distance tab between the centers of the atoms, the result would be a curve having a shape like that seen in Fig. 5-1. This is a bond dissociation curve, the path from the minimum (the equilibrium intemuclear distance in the diatomic molecule) to increasing values of tab describing the dissociation of the molecule. It is conventional to take as the zero of energy the infinitely separated species. 

Figure 6-19. Bond dissociation curve showing the different zero-point vibrational energies of isotopic species R-H and R-D.

Figure 6-20. Bond dissociation curve showing that the average R-H bond distance is greater than the R-D bond distance because of their zero-point energy difference.

Figure 11.1 shows the bond dissociation curve at the HF level with the STO-3G, 3-21G, 6-31G(d,p), cc-pVDZ and cc-pVQZ basis sets. The total energy drops considerably upon going from the STO-3G to the 3-21G and again to the 6-3IG(d,p) basis. This is primarily due to the improved description of the oxygen Is-orbital. The two different... 

Figure 11.1 Bond dissociation curves for H2O at the HF level, absolute energies...

Figure 11,13 Bond dissociation curve for unrestricted DPT methods...

The treatment of loss of R from sterns is trivial dissociation occurs along some kind of bond dissociation curve to give, in the imagined limit, metal and a car-banion. In solution at least, both fragments will interact with the environment at bond distortion energies wefl below the dissociative limit. 

It is known from spectroscopic studies that bond-dissociation curves are simulated very well by the Morse function ... 

Relativistic Methods 204 8.1 Connection Between the Dirac and Schrodinger Equations 207 8.2 Many-particle Systems 210 8.3 Four-component Calculations 213 11.4.1 Ab Initio Methods 272 11.4.2 DFT Methods 273 11.5 Bond Dissociation Curve 274 11.5.1 Basis Set Effect at the HF Level 274 11.5.2 Performance of Different Types of Wave Function 276... 

Displacement from equilibrium (A) Figure 4.7 Bond dissociation curves for H2... 

Bodenstein approximation, 101 Boltzmann constant, 202 Boltzmann distribution, 157, 201 Bond dissociation curve, 191, 293 Bond dissociation eneigy, 196 Bond order, 223 Borderline reactions, 429 Bom equation, 408... 

Cuts through the surfaces of Figure 4.23 at various constant values of d give the n -bond dissociation curves of polar bonds. The different values of d could be achieved intramolecularly, by a suitable variation of the molecular geometry, or intermolecularly, by changes in the molecular environment, or even by such modifications in the molecular composition itself as changes in the substituents on the double bond or in the nature of the doubly bonded atoms. 

Figure 11.1 shows the bond dissociation curves at the HF level with the STO-3G, 3-21G, 6-31G(d,p), cc-pVDZ and cc-pVQZ basis sets. 

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