The molecular structure of WCl 6 is octahedral (O h ) , but WH 6 is trigonal prismatic (D 3h ) . a) Derive the irreducible representations that are…

The molecular structure of WCl6   is octahedral (Oh) , but WH6 is trigonal prismatic (D3h) .   
 a) Derive the irreducible representations that are spanned by the six σ bond vectors of  WH6 . 
b/  What 5d, 6s and 6p orbitals of W have the proper  irreducible representations to have the potential for use in forming σ bonds in WCl6 (Oh) and WH6  (D3h) ?
c/ Describe whether or not it is possible to distinguish an octahedral structure from a trigonal prismatic geometry using only the number of observed infrared WX6  stretching vibrational modes .
d/ Construct a schematic molecular orbital diagram for WH6 using the tungsten 5d , 6s and 6p and the hydrogen 1s orbitals as the valence orbitals and place the proper number of valence electrons into the molecular orbitals.