Soft excitation modes of quantum Bose fluids in the liquid-solid phase transition

We search for signatures of the liquid-solid phase transition in a group of strongly correlated quantum Bose fluids. We identify the non-spherically symmetric excitation mode which becomes soft at the critical density as the driving mechanism of the phase transition. The symmetry of the soft mode indicates the point-group symmetry of the arising solid phase. We place special emphasis on, examining the effect of the short- and long-range features of the interaction on the crystal structure. Where possible, comparison with experiments and Monte Carlo results is made and a good agreement in the critical densities is found. The analysis reveals new features in the phase diagram of the charged Bose fluid.