Charge density and chemical bonding in rutile, TiO2.

The low-order structure factors of rutile (TiO(2)) have been measured with an accuracy of up to 0.09% by quantitative convergent-beam electron diffraction (QCBED). This error is an order of magnitude smaller than that in conventional Bragg X-ray diffraction and equivalent to the accuracy of the X-ray Pendellösung method. It is sufficient to distinguish atomic, covalent and ionic bonding. By refinement of the combined data of low-order reflections measured by electron diffraction with high-order reflections from X-ray diffraction, accurate charge-density maps are obtained and used to understand the role of the 3d electrons in Ti-O bonding. The results are combined with electron energy-loss spectra (EELS) in a study of the electronic structure.

[1]  J. C. H. Spence,et al.  Electron Microdiffraction , 2020, Springer US.

[2]  K. Schwarz,et al.  Electronic structure calculations of solids using the WIEN2k package for material sciences , 2002 .

[3]  J. Zuo,et al.  Direct observation of d-orbital holes and Cu–Cu bonding in Cu2O , 1999, Nature.

[4]  Saunders,et al.  Quantitative zone-axis convergent-beam electron diffraction (CBED) studies of metals. I. Structure-factor measurements. , 1999, Acta crystallographica. Section A, Foundations of crystallography.

[5]  P. Coppens,et al.  Nonlinear Least‐Squares Fitting of Numerical Relativistic Atomic Wave Functions by a Linear Combination of Slater‐Type Functions for Atoms with Z = 1–36 , 1998 .

[6]  J. Zuo,et al.  Charge Density of MgO: Implications of Precise New Measurements for Theory , 1997 .

[7]  R. Holmestad,et al.  Efficient beam-selection criteria in quantitative convergent beam electron diffraction , 1996 .

[8]  J. Zuo,et al.  Ultramicroscopy Letter Electron detection characteristics of slow-scan CCD camera , 1996 .

[9]  J. Zuo,et al.  On the beam selection and convergence in the Bloch wave method , 1995 .

[10]  K. Schwarz,et al.  Chemical bonding in rutile-type compounds , 1992 .

[11]  K. Weyrich.  “Frozen” phonon calculations: Lattice dynamics and -Instabilities , 1990 .

[12]  G. Sawatzky,et al.  Oxygen 1s x-ray-absorption edges of transition-metal oxides. , 1989, Physical review. B, Condensed matter.

[13]  Timothy Hughbanks,et al.  Structural-electronic relationships in inorganic solids: powder neutron diffraction studies of the rutile and anatase polymorphs of titanium dioxide at 15 and 295 K , 1987 .

[14]  P. Coppens,et al.  Generalized relations between d-orbital occupancies of transition-metal atoms and electron-density multipole population parameters from X-ray diffraction data , 1983 .

[15]  M. O'Keeffe.  On the Arrangements of Ions in Crystals , 1977 .

[16]  P. Trucano,et al.  Structure of graphite by neutron diffraction , 1975, Nature.

[17]  P. Goodman.  Role of upper-layer interactions in electron diffraction symmetries , 1974, Nature.

[18]  Philip Coppens,et al.  X-ray charge densities and chemical bonding , 1997 .

[19]  W. Gonschorek.  X-ray charge density study of rutile (TiO2) , 1982 .

[20]  K. Kurki-suonio.  IV. Symmetry and its Implications , 1977 .