title: Calculation of the crystal densities of molecular salts and hydrates using additive volumes for charged groups.
abstract: Standard group volumes which can be used to estimate the crystal densities of molecular salts and hydrates are reported, as a complement to values derived recently for the functional groups of neutral organic compounds. These new parameters were derived from a least-squares fit of cell volumes for a set of 1132 ionic molecular crystals from the Cambridge Structural Database. Their values point to the unusual overlap between monovalent O atoms and neighbouring H atoms. Using the new group volumes presently obtained, the crystal densities of the salts are predicted with an average error of <2.5%, while previous atom-based schemes yield average errors of >3%. To illustrate the possible application of the present database, the problem of designing environmentally friendly propellants is addressed.
authors.affiliation: Commissariat à l'Energie Atomique, Centre du Ripault, BP16, F-37260 Monts, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Beaucamp
authors.forename: Nicolas
authors.initials: N
authors.lastname: Marchet
authors.forename: Didier
authors.initials: D
authors.lastname: Mathieu
authors.forename: Viatcheslav
authors.initials: V
authors.lastname: Agafonov