Coherent X‐Ray Scattering for the Hydrogen Atom in the Hydrogen Molecule

  title={Coherent X‐Ray Scattering for the Hydrogen Atom in the Hydrogen Molecule},
  author={Robert F. Stewart and Ernest R. Davidson and William Turner Simpson},
  journal={Journal of Chemical Physics},
The x‐ray form factors for a bonded hydrogen in the hydrogen molecule have been calculated for a spherical approximation to the bonded atom. These factors may be better suited for the least‐squares refinement of x‐ray diffraction data from organic molecular crystals than those for the isolated hydrogen atom. It has been shown that within the spherical approximation for the bonded hydrogens in H2, a least‐squares refinement of the atomic positions will result in a bond length (Re value) short of… 
Modeling of the nuclear parameters for H atoms in X-ray charge-density studies.
The results from the topological analysis of these systems confirm the success of the 'best anisotropic' model in providing parameters for the H atoms that give charge densities in agreement with the reference models based on H-atom parameters derived from neutron diffraction.
X-ray and electron scattering from diatomic molecules in the first Born approximation
The total and elastic x‐ray scattering intensities from the diatomic molecules CO, N2, and O2 have been calculated within the Waller–Hartree theory. Near Hartree–Fock quality wavefunctions with
Generalized x‐ray scattering factors in diatomic molecules
Generalized x‐ray scattering factors for atoms (pseudoatoms) in diatomic molecules are determined from a finite multipole expansion of the charge density about each nucleus. The Fourier–Bessel
Valence Structure from Coherent X‐Ray Scattering: Fourier Difference Synthesis
The one‐electron density function for a molecule of first‐row atoms is partitioned into core‐electron and valence‐electron density pieces. The SCF 1s AO's are used to define the core‐electron density
Valence Structure from X‐Ray Diffraction Data: An L‐Shell Projection Method
Generalized x‐ray scattering factors, in a simplified form, have been applied to several organic molecular crystals. Atomic charge parameters for L‐shell scattering factors have been determined from
Hydrogen atoms can be located accurately and precisely by x-ray crystallography
It is shown that, contrary to widespread expectation, hydrogen atoms can be located very accurately using x-ray diffraction, yielding bond lengths involving hydrogen atoms (A–H) that are in agreement with results from neutron diffraction mostly within a single standard deviation.
Density-optimized radial exponents for X-ray charge-density refinement from ab initio crystal calculations.
The relation between atomic charge and kappa offers the possibility of introducing a constraint in the charge-density refinement of very large molecules, for which reduction of the size of the parameter set may be essential.
Atomic charges, dipole moments, and Fukui functions using the Hirshfeld partitioning of the electron density
Condensed Fukui functions for a large number of molecules, undergoing an electrophilic or a nucleophilic attack, are computed and compared with the HOMO and LUMO densities, integrated over the Hirshfeld atoms in molecules.


The Normal State of the Hydrogen Molecule
A simple wave function for the normal state of the hydrogen molecule, in which both the atomic and ionic configurations are taken into account, was set up and treated by a variational method. The
Hydrogen Atom Thermal Parameters
The indicated trend for this compound, along with other results, provides the basis for a possible explanation of the anomolous values that have been obtained for hydrogen atom thermal parameters.
The Physical Nature of the Chemical Bond
The quantum mechanical wave functions of molecules are discussed. An attempt is made to effect a simultaneous regional and physical partitioning of the molecular density, the molecular pair density,
Natural Expansion of Exact Wavefunctions. II. The Hydrogen‐Molecule Ground State
The Kolos and Roothaan wavefunction for H2 has been analyzed into natural orbitals. It was found that the first natural orbital is nearly the SCF function. The first four natural orbitals provide a