Notes for Authors

X-ray and Electron Diffraction Study of MgO

Precise X-ray and electron diffraction studies of MgO have been performed. Experimental structure amplitudes have been compared with those calculated by the non-empirical Hartree–Fock method and analysis of both experimental and theoretical electron densities and electrostatic potentials is described.

Investigation into the Crystal Structure of the Perovskite Lead Hafnate, PbHfO₃

Polycrystalline neutron diffraction and low-temperature single crystal X-ray diffraction are used to investigate the room- temperature phase of lead hafnate, PbHfO₃. The octahedral distortion and cation shifts arising in this pseudo-cubic perovskite are compared with those of the technologically important material PbZrO₃.

Experimental Electron Density Study of NaH₂PO₄ at 30 K

The deformation electron density of NaH₂PO₄ has been studied at 30 K as a reference for the electron-density characteristics of hydrogen-bonded ferroelectrics containing phosphate ions and the effective charges were obtained.

Distribution of the M-M Distances in the Oxides of the Group 13 Elements and their Spinels and Delafossites

The M-M distances (M = Al, Ga, In, Tl), in their oxides, are not distributed uniformly, but present maxima at values near the corresponding distances in the pure metals.

Intermolecular Force-Field Parameters for Boron Hydrides

A new computer program, nbp, is used to fit a training set of 15 borane crystal structures with an (exp-6-1) intermolecular force field.

Intermolecular N-H⋯O Hydrogen Bonding Assisted by Resonance. II. Self Assembly of Hydrogen-Bonded Secondary Enaminones in Supramolecular Catemers

Structures of compounds containing the 2-en-3-amino-1-one heterodienic system are investigated; they form intermolecular N-H⋯O resonance-assisted hydrogen bonds by which the molecules are connected in infinite chains. The effects of the substituents on the enaminonic systems and the chain morphologies are analyzed in order to discover crystal engineering rules to predict and interpret crystal packings.

Experimental Electron-Density Study of 4-Cyanoimidazolium-5-olate at 120 K

The experimental electron density study of 4-cyanoimidazolium-5-olate at 120 K shows details of its molecular mesoionic structure.

Nucleophile–Electrophile Interactions in 1,8-Disubstituted Naphthalenes: Structures of Three 1-Naphthaldehydes and a 1-Naphthyl Methyl Ketone

Crystal structures of several 8-oxygenated 1-naphthaldehydes and 1-naphthyl methyl ketones indicate that the carbonyl group in the former approaches coplanarity with the naphthalene ring, while in the latter it approaches orthogonality. This difference in behavior is discussed in terms of steric effects and C-H⋯O interactions.

Temperature-Dependent Phase Transitions in Two Crystalline Host–Guest Complexes Derived from Mandelic Acid

The crystal structures of two inclusion complexes of mandelic acid derivatives and DMF [(1) and (2)], which show reversible solid–solid phase transitions dependent on temperature, have been established for both crystal forms [170 and 250 K, and 170 and 270 K] of (1) and (2), respectively.

Structural and computational analysis of published neutron diffraction data show that crystalline vitamin B₁₂ coenzyme contains a strong intramolecular N-H⋯Ph hydrogen bond

The neutron diffraction crystal structure of vitamin B₁₂ coenzyme contains an intramolecular N-H⋯Ph hydrogen bond with an energy of ca 16.7 kJ mol⁻¹.