List of contributors. Preface (M. Hargittai, I. Hargittai). Reminiscences of X-ray structure analysis (D.W.J. Cruickshank). Lattice energy methods for inorganic molecular solids (U. Englert). Molecular solids: self-assembled host-guest organometallic aggregates (H.W. Roesky, I. Haiduc). Recent advances in studying tautomerism in solution and in the solid state (E. Kleinpeter). BE2 (AQ) hydrolysis and complexation: using calculated and experimental 9BE NMR shifts to determine BE speciation in solution (J.A. Tossell). CH...O hydrogen bonding (S. Scheiner). Isolated, solvated, and complexed nucleic acid bases: structures and properties (J. Leszczynski). How to design stable silylenes? (T. Veszpremi). Development of dynamic model in gas electron diffraction (V.P. Novikov, L.V. Vilkov). The volumes of atoms (S. Hovmoeller, K. Okamoto). Atomic volumes in inorganic chemistry (L.E. Depero). Structural parameters and conformational stabilities of some monosubstituted methyl cyclopropanes and oxiranes (J.R. Durig). Some relationships between molecular structure and thermochemistry: part 4 (J.F. Liebman, S.W. Slayden). Index.