17 research outputs found
High-quality variational wave functions for small 4He clusters
We report a variational calculation of ground state energies and radii for
4He_N droplets (3 \leq N \leq 40), using the atom-atom interaction HFD-B(HE).
The trial wave function has a simple structure, combining two- and three-body
correlation functions coming from a translationally invariant
configuration-interaction description, and Jastrow-type short-range
correlations. The calculated ground state energies differ by around 2% from the
diffusion Monte Carlo results.Comment: 5 pages, 1 ps figure, REVTeX, submitted to Phys. Rev.
The helium trimer with soft-core potentials
The helium trimer is studied using two- and three-body soft-core potentials.
Realistic helium-helium potentials present an extremely strong short-range
repulsion and support a single, very shallow, bound state. The description of
systems with more than two helium atoms is difficult due to the very large
cancellation between kinetic and potential energy. We analyze the possibility
of describing the three helium system in the ultracold regime using a gaussian
representation of a widely used realistic potential, the LM2M2 interaction.
However, in order to describe correctly the trimer ground state a three-body
force has to be added to the gaussian interaction. With this potential model
the two bound states of the trimer and the low energy scattering helium-dimer
phase shifts obtained with the LM2M2 potential are well reproduced.Comment: 15 pages, 3 figures, submitted to Few-Body System
Beugung von Atom-, Molekular- und Clusterstrahlen an nanostrukturierten Transmissionsgittern
SIGLEAvailable from TIB Hannover: RA 1396(1999/7) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman