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A simple method is described for calculation of character tables for the symmetry group of molecules consisting of a number of CH$_3$, group attached to a rigid framework.
The restricted NRG of this molecule is seen to be group of order 324 and it has a point-group symmetry C$_{2v}$. We prove that it is a group with 33 conjugacy classes and also we compute the character tables of this group.
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