Applications to the n-Conjugated Molecules

Analogous to the bond orders in the MO approaches, / ., as defined in Eq. (38), which stands for the probability of finding a singlet arrangement between atoms i and j [38], has been introduced as an index to correlate with the bond lengths of BHs. 

The reason for choosing this index is because the VB energy of a molecule can be partitioned into the sum of the probabilities of finding local singlet arrangements on its various bonds, as shown in Eq. (39). 

As a result, one may expect that p v could measure the strength of the i-j bond and correlate with the i-j bond length. A good linear correlation (Fig. 2) between the calculated ground-state p and the experimental bond lengths of several BHs (displayed later in Table 3) encouraged us to apply these pstj values 

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