The main postulates of VSEPR theory are as follows :
(i) The shape of a molecule depends upon the number of valence shell electron pairs around the central atom.
(ii) Pairs of electrons in the valence shell repel one another since their electron clouds are negatively charged.
(iii) There pairs of electrons tends to occupy such position in space that minimize repulsion and thus maximize distance between them.
(iv) The valence shell is taken as a sphere with the electron pairs localizing on the sphere at maximum distance from one another.
(v) A multiple bond is treated as it is a single electron pair and two or three electron pairs of a multiple bond is treated as super pair.
(vi) When two or more resonance structures can represent a molecule, the VSEPR nodal is applicable to any such structure.
