Approximate kinetic energy density for intermolecular regions in hydrogen bond dimers

In a recent paper, Abramov [Y.A. Abramov, Acta Cryst. A53 (1997) 264] has proposed an approximation to compute the kinetic electron density G(r) from any electron density rho (r) in the form of a truncated gradient expansion. This approach uas known to provide accurate estimates of G(r) at the bond critical points of rho (r). We show that Abramov's approach can be reliably used in spatial intermolecular regions in hydrogen fluoride and water dimers to obtain accurate estimates of the kinetic electron density. The study shows the usefulness of this approximated G(r) for quantum studies of intermolecular interactions in terms of rho (r). (C) 2001 Elsevier Science B.V. All rights reserved.