Computable Error Bounds in the Finite-Element Method

In order to provide computable error bounds in the finite-elementmethod, attention is mainly focused on specifying the constantsin convergence results. In the present note we demonstrate adifferent approach, namely a local-interpolation error-estimationtechnique that does not separate powers of the discretizationparameter h. It provides a bound for the relative error overarbitrary triangular grids which, in particular, characterizesthe influence of irregular grids.     

Buoyancy corrections for the potential of an impurity in a 4He nanodroplet

This paper presents correction terms for the effective potential for the translation and rotation of an impurity atom or molecule solvated in a helium nanodroplet that were previously published (Lehmann, K. K., 1999, Molec. Phys., 97, 645). The correction arises from changes in the total He-He potential energy of the displaced liquid as a function of the solute position within the droplet. For the alkali atoms, this buoyancy type correction removes the large barrier to ejection of the atom from the droplets, which is predicted if this term is neglected.