From woon@hecla.molres.org Wed Apr 26 11:47:31 1995 Date: Mon, 24 Apr 1995 10:50:54 -0700 From: David Woon The problem is that in the gas phase, HF will dissociate to H + F. Dissociation into H+ + F- costs E(IP of H) - E(EA) and amounts to several eV or more for most diatomics (IP=ionization potential; EA= electron affinity). The ions are only more stable relative to the the atoms in solution. You could try doing the dissociation with a solva- tion reaction field turned on (Gaussian lets you do this, for example), but I couldn't predict how reasonable this with be. I suspect getting the right charges will require explicit quantum mechanical treatment of the first solvation shell. You may find our recent work on the dissociation of alkali halides to be of interest [DE Woon & TH Dunning, Jr., JACS 117, 1090 (1995)]. David E. Woon | woon@hecla.molres.org Molecular Research Institute | or woon@purisima.molres.org 845 Page Mill Road | (415)424-9924 (voice) Palo Alto, CA 94304 | (415)424-9501 (fax) ---------------------------------------------------------------------------