Self‐similar wavepackets for describing warm dense matter

Using the time dependent variational principle, we develop a general formulation of single particle quantum dynamics within the assumption that the wavepacket's density remains self‐similar. We obtain the amplitudephase relationship from the continuity equation. We investigate the ground state properties of waves with Gaussian and exponential densities in hydrogenic and helium‐like systems. We show that the exponential wavepackets yield superior ground state energies ‐ an important advantage in describing warm dense matter ( T < 50 eV) in which bound states form. Exponentials yield an improved ground state energy for molecular hydrogen, but with a bond length 13% short of the experimental value. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)