We have studied the molecular orbitals of ruthenium (II) bromide, in order to study the
extent of contribution of 4d, 5s and 5p orbitals in the formation of molecular orbitals. The
3D modeling and geometry optimization of the ruthenium (II) bromide have been done by
CAChe software using molecular mechanics with EHT option. Eigenvector analysis shows
that 4dx2-y2 and 4dxy orbitals of ruthenium play a major role in bonding between ruthenium
and bromide, 5s orbital is next and 4p orbitals have a negligible role. There is a difference
in energy levels of s and p orbitals of bromide are 0.6090 eV. The overlap population
analysis shows that the nonbonding orbitals are present in 6th and 7th molecular orbitals. No
molecular orbital is formed by only two atomic orbitals. All molecular orbitals have
contribution from many atomic orbitals; the difference is only in extent of involvement.
