Valence shell electron pair repulsion (VSEPR) theory is based on the simple idea that electron groups one another through coulombic forces. ... According to VSEPR theory, the repulsions between electron groups on the atom of a molecule determine the geometry of the molecule. The preferred geometry of a molecule is the one in which the electron groups have separation possible. Consequently, for molecules having just one central atom, molecular geometry depends on (a) the of electron groups around the central atom and (b) how many of those electrons groups are