Valence-shell electron-pair repulsion square planar shape

The valence shell of the xenon atom contains 12 electrons eight from the xenon and one each from the four chlorine atoms. There are four bonding pairs and two lone pairs. The basic shape adopted by the molecule Is octahedral. Flowever, there are two possible arrangements for the lone pairs. The first structure, square planar, minimizes the repulsion (the lone pairs are at 180° to each other) and Is hence adopted as the molecular shape (Figure 14.7). As a general rule, for a molecule where the electron domains adopt an octahedral structure, any lone pairs will occupy positions opposite to one another. 

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