The experimental electron density in lithium hydroxide monohydrate

Hermansson, Kersti; Thomas, Josh

doi:10.1107/s0567740882009376

Cited by 35 publications

(22 citation statements)

References 6 publications

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“…In all the cases here, the calculations were based on the experimental neutron-diffraction determined structure. These maps can be directly compared with the corresponding experimental maps by Hermansson & Thomas (1982) (note, however, that in our calculation, Li instead of Li + is subtracted in the maps). The experimental density was corrected for thermal motion, so that effectively zero-K density maps were obtained.…”

Section: Electron Densitiesmentioning

confidence: 99%

Section: Crystal Structurementioning

confidence: 99%

“…The crystal structure and deformation electron density of LiOH.H20 have been studied experimentally by a combination of X-ray and neutron diffraction measurements at 295 K (Hermansson & Thomas, 1982); see Table 1. The crystallographic unit cell is fairly small, with four asymmetric units Hermansson & Thomas, 1982) The experimental neutron-diffraction determined atomic positions are given for the five atoms in the asymmetric unit and are expressed as fractional cell coordinates.…”

Section: Crystal Structurementioning

confidence: 99%

“…Molecular crystals have not been much studied by periodic calculations; the electron density of urea by Dovesi, Causfi, Orlando, Roetti & Saunders (1990) was a pilot study. The crystal under study here is LiOH.H20, an ionic hydrate where the water molecule is strongly bound, as is manifested by the short H...O distance [1.684(1)A] (Hermansson & Thomas, 1982), the large OH frequency downshift (-930cm-~) (Berglund et al, 1978) and the low 2H quadrupole coupling constant (173kHz) (Clifford, Smith & Temme, 1975). There are several reasons behind our choice of this compound for a periodic HartreeFock study.…”

Section: Introductionmentioning

confidence: 99%

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Structural, vibrational and electronic properties of a crystalline hydrate from ab initio periodic Hartree–Fock calculations

Ojamäe¹,

Hermansson²,

Pisani³

et al. 1994

Acta Crystallogr Sect B

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The hydrate crystal lithium hydroxide monohydrate LiOH.H20 has been studied by ab initio periodic Hartree-Fock calculations. The influence of the crystalline environment on the local molecular properties (molecular geometry, atomic charges, electron density, molecular vibrations and deuterium quadrupole coupling constants) of the water molecule, the lithium and hydroxide ions has been calculated. A number of crystalline bulk properties are also presented; optimized crystalline structure, lattice energy and electronic band structure. The optimized cell parameters from calculations with a large basis set of triple-zeta quality differ by only 1-3% from the experimental neutron-determined cell, whereas the STO-3g basis set performs poorly (differences of 5-10%). With the triple-zeta basis also the atomic positions and intermolecular distances agree very well with the experiment. The lattice energy differs by -8% from the experimental value, and by at most 3% when a density-functional electron correlation correction is applied. Large electron-density rearrangements occur in the water molecule and in the hydrogen bond and are in qualitative and quanti-© 1994 International Union of Crystallography Printed in Great Britain -all rights reserved tative agreement with experimental X-ray diffraction results. The quadrupole-coupling constants of the water and hydroxide deuterium atoms are found to be very sensitive to the O---H bond length and are in good agreement with experimental values when the calculation is based on the experimental structure. The anharmonic O--H stretching vibrations in the crystal are presented and found to be very close to results from calculations on molecular clusters. The electronic band and density-of-states spectra are discussed. Model calculations on a hydrogen fluoride chain were used to rationalize the results. IntroductionThe water molecule and its unique binding properties are of interest to both experimentalists and theoreticians. Crystalline hydrates have consequently been extensively characterized experimentally. The effect of the crystalline environment on the structure, vibrations, electron density, quadrupolar coupling constants etc. of the water molecule have been investigated in many hundreds of diffraction and spectroscopic studies (e.g. Falk & Knop, 1973; Acta Crvstallographica Section B ISSN 0108-7681 ©i994 LARS OJAMAE et al. 269 Olovsson & J6nsson, 1976; Berglund, Lindgren & Tegenfeldt, 1978a,b; Chiari & Ferraris, 1982;Hermansson, 1984;Mikenda, 1986;Lutz, 1988). Among the crystalline hydrates one finds examples of a wide variety of water environments, from very weakly to very strongly bound molecules. This is reflected in the broad ranges of measured H-..O hydrogen-bond distances (from, say, 3.2 down to 1.65 A0, OH vibrational frequency downshifts (from -150 to --1000 cm-~) and deuteron quadrupole coupling constants (from 240 down to -170 kHz for the most strongly bound water molecules).The theoretical approach to the study of hydrates has commonly been to use q...

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Section: Electron Densitiesmentioning

confidence: 99%

Section: Crystal Structurementioning

confidence: 99%

Section: Crystal Structurementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Structural, vibrational and electronic properties of a crystalline hydrate from ab initio periodic Hartree–Fock calculations

Ojamäe¹,

Hermansson²,

Pisani³

et al. 1994

Acta Crystallogr Sect B

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“…As the convergence of earlier refinements with exponential radial functions e -'r was often difficult (Legros & Kvick, 1980;Hermansson & Thomas, 1982), Gaussian radial functions were used initially, the exponents y being assigned constant values of 3"5 A-2 (Lundgren, 1979). Deformation functions up to the octapole level (n <-3) were assigned to the non-hydrogen atoms but were limited to the quadrupole level (n <_ 2) for hydrogen atoms.…”

Section: Structure Refinementsmentioning

confidence: 99%

An experimental electron density study of NaHC₂O₄.H₂O at 120 K

Delaplané¹,

Tellgren²,

Olovsson³

1990

Acta Crystallogr Sect B

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Sodium hydrogen oxalate monohydrate, Mr = 130.03, triclinic, P1, a = 6.4235 (7), b = 6.6580 (8), c = 5.6941 (10) A, a : 85-048 (9), /3= 110.100 (13), y = 104.963 (14) °, V = 220.94/~3, Z = 2, Dx = 1.954 Mg m -3, A(Mo Ka) = 0.71069/~, /1, = 0.293 mm-l, F(000) = 132, T = 120 K, R = 0.0279 for conventional refinement based on 3971 reflections with Fo 2 > 3tr(F2). The deformation electron density of NaHC2Oa.H20 has been measured at 120 K using X-ray and neutron diffraction techniques. X-X (high order) and X-N difference density maps are compared with deformation maps derived from a multipole model. Deformation densites in the covalent bonds of the HC204 ion are correlated with bond order. Deformation densities in the three independent hydrogen bonds are consistent with an electrostatic model for bonds of weak to intermediate strength in which polarization and other contributions become more important as the protonacceptor distance decreases. The hydrogen bonding affects both the covalent bonds and the lone-pair electron density of the acceptor oxygen atoms.

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Charge Density Distribution and Bond Characterization of 2,2′‐Dipyridylamine (Hdpa): A Combined Study of Experiment and Theory

Lee

Chen

et al. 2013

J Chinese Chemical Soc

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Electron density distribution of 2,2′‐dipyridylamine (Hdpa) is studied by single‐crystal X‐ray diffraction method at 120 K. Structural determination reveals that the conformation of Hdpa molecule is the syn‐anti conformation caused by the intramolecular N···H‐C hydrogen bond between two pyridine rings. Two Hdpa molecules flock together via two intermolecular N···H‐N hydrogen bonds to form a dimer. Bond characterization is made in terms of deformation density (Δρ), topological analysis of total electron density based on multipole model and molecular orbital (DFT) calculation. The agreement between experiment and theory is good. The topological properties of bond critical points at C‐C, C‐N, N‐H and C‐H bonds are reasonable and reveal a covalent bond character with the high ρ(rc), negative ∇2ρ(rc) and negative total energy density H((rc) values. A low ρ(rc) and positive ∇2ρ(rc) of bond critical points at N···H bonds reveal a closed‐shell interaction for C‐H···N and N‐H···N hydrogen bonds. The π‐delocalization feature around the pyridine ring is also performed by bond ellipticity (ϵ) and fermi‐hole distribution.

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The experimental electron density in lithium hydroxide monohydrate

Cited by 35 publications

References 6 publications

Structural, vibrational and electronic properties of a crystalline hydrate from ab initio periodic Hartree–Fock calculations

Structural, vibrational and electronic properties of a crystalline hydrate from ab initio periodic Hartree–Fock calculations

An experimental electron density study of NaHC₂O₄.H₂O at 120 K

Charge Density Distribution and Bond Characterization of 2,2′‐Dipyridylamine (Hdpa): A Combined Study of Experiment and Theory

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The experimental electron density in lithium hydroxide monohydrate

Cited by 35 publications

References 6 publications

Structural, vibrational and electronic properties of a crystalline hydrate from ab initio periodic Hartree–Fock calculations

Structural, vibrational and electronic properties of a crystalline hydrate from ab initio periodic Hartree–Fock calculations

An experimental electron density study of NaHC2O4.H2O at 120 K

Charge Density Distribution and Bond Characterization of 2,2′‐Dipyridylamine (Hdpa): A Combined Study of Experiment and Theory

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An experimental electron density study of NaHC₂O₄.H₂O at 120 K