For the lanthanoids, the 4f orbitals are small and do not participate in bonding. Assume however that the 4f orbitals are big enough to participate in bonding alongside with the 6s orbitals.
Draw the expected trend in the melting temperatures for the lanthanides starting with La and ending with Yb. Support your conclusions by showing the DOS and bonding character plots for the element with the highest melting temperature.
Note: assume that the d orbitals do not participate in bonding and a d-electron is donated to the 4f shell. Neglect the lanthanoid contraction. The trend obtained will be different from the real melting temperatures.