Stable structure of heavy alkalis in the pseudopotential formalism

Structural energies of the three heavy alkali metals, namely K, Rb and Cs, have been calculated in the energy-independent model pseudopotential formalism. For K and Cs, BCC structure is found to have the lowest energy. For Rb, although the BCC phase is favoured over the FCC phase, it is seen to have an energy higher than the HCP phase, but with a relatively small difference. The results of this work have been compared with those from other pseudopotential calculations. An attempt has also been made to compute the structure with the lowest energy for different polymorphs of Cs.