I inititated an international effort through IUPAC to come-up with a modern
definition of the hydrogen bond. The task group formed by IUPAC has
recently submitted a recommendation for the definition of hydrogen bond
and a technical report that provides the rationale for the proposed definition
and also a summary of hydrogen bond reasearch over the past century.
Link to IUPAC website with the recommendation:
http://media.iupac.org/reports/provisional/abstract11/arunan_310311.html
Link to my home-page where the activities of IUPAC project have been given
http://ipc.iisc.ernet.in/~arunan/iupac/
http://ipc.iisc.ernet.in/~arunan/IUPAC1/
Comments can be sent to arunan@ipc.iisc.ernet.in