VSEPER

  Exclusion of the three electrons in the molecule as follows: solitary the repulsion between the electrons(lone-lone exclusion); solitary electronic and bonding electron repulsion between the (solitary - into exclusion); bonding electron pairs ofrepulsion between the (into the  - into the exclusion).  Molecules will try to avoid such exclusion to maintain stability.  Exclusion can not be avoided, the molecules tend to form a rejection of the weakest structures.  Lone pair repulsion between the electrons is electronic and bonding, which in turn is greater than the repulsion between the bonding electron pairs.  Therefore, the molecules tend to be the weakest into- into exclusion.