Firstly, I found the RHF expansion of $\Phi_2$ and $\Phi_3$ is not symmetric at equation (4.29). Then I expand $\Phi_2$ by myself, the results showed it's 

$
\Phi_2 = (\chi_A\chi_A-\chi_B\chi_B)(\alpha\beta-\beta\alpha) - (\chi_A\chi_B-\chi_B\chi_A)(\alpha\beta+\beta\alpha)
$

Moreover, even with this the equation (4.30)~(4.31) is also inconsistent, which the righthand side of the equation should be switched. 

But this is a famous book in its third edition, so am I misunderstood or there is an error?

[![The UHF Dissociation and the Spin Contamination Problem][1]][1]

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**Reference:**


<sup>(1)	Jensen, F. Introduction to Computational Chemistry, 3rd ed.; John Wiley & Sons: Nashville, TN, 2017.</sup>



  [1]: https://i.sstatic.net/8zp3N.png