Boundary contributions to the hypervirial theorem
  It is shown that under certain boundary conditions the virial theorem has to be modified. We analyze the origin of the extra term and compute it in particular examples. The Coulomb and harmonic oscillator with point interaction have been studied in the light of this generalization of the virial theorem. 
J. G. Esteve, F. Falceto and Pulak Ranjan Giri
quant-ph hep-th