Orbitals and Bond Angles for Multiple Bonds

For a double bond, as in ethylene, two orbitals of each of the two bonded atoms are required. There are two alternative ways in which 

When the quantum mechanical equations are examined it is found that the two descriptions of the double bond are identical in the molecular-orbital treatment based on s-p hybrids.76 They are not identical 

Hall and J. Lennard-Jones, Proc. Roy. Soc. London A205, 357 (1961). 

Compound Meth- od Angle Value Refer- ence 

Hughes, A, B. Biswas, and J. N. Wilson, unpublished research, Calif. Inst. Tech. 

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