What's the difference between rhombohedral and triclinic?

Rhombohedral


Definition:

  • (a.) Related to the rhombohedron; presenting the form of a rhombohedron, or a form derivable from a rhombohedron; relating to a system of forms including the rhombohedron and scalenohedron.

Example Sentences:

  • (1) Crystal structure analysis and refinement at 2.0 A resolution of a rhombohedral crystal form of human annexin V at high calcium concentration revealed a domain motion compared to the previously analysed hexagonal crystal form.
  • (2) Hexagonal rods were compared to rectangular or rhombohedral rods.
  • (3) Assuming the organic template covers the crystal exterior, the projected rhombohedral segment, appearing hexagonal, would seem to contain the protein, hence explaining the apparent presence of the crystal ghost.
  • (4) Furthermore, under conditions known to lead to the formation of rhombohedral crystals of canavalin, a limiting size is reached at high concentrations of canavalin.
  • (5) The inspection of these surfaces using SEM and EDX revealed hexahedrally based crystals including pseudocuboidal, rhombohedral and variable rugged rocky shapes.
  • (6) Detailed analysis of the structure of a single bilaminar lamella shows that each sheet of the two-sheet structure is identical and made up of repeating rhombohedral units whose principal axes are in the ratio of 2:1.
  • (7) The crystals were rhombohedral with an edge length of 0.4 mm.
  • (8) Whereas segments of hexagonal rods in the section should project as octagons at the electron microscope imaging plane, and octagonal profiles are never found, rectangular or rhombohedral rod segments project as hexagons.
  • (9) Precession photographs show that they belong to the rhombohedral space group R3 with unit cell dimensions a = b = 145.4 A, c = 47.5 A, alpha = beta = 90 degrees and gamma = 120 degrees.
  • (10) In naturally desensitized areas on the same dentin surface, most of the dentinal tubules were obturated with rhombohedral crystals of all sizes; membranous structures were not observed in these tubules.
  • (11) The paper describes the arrangement of the atoms within rhombohedral crystals of 2Zn pig insulin as seen in electron density maps calculated from X-ray data extending to 1.5 A (1 A = 10(-10) m = 10(-1) nm) at room temperature and refined to R = 0.153.
  • (12) Rhombohedral crystals grow in 1.8 to 2.0 M ammonium sulfite, pH 7.8 at 21 degrees C, and tetragonal crystals grow in 2.6 M magnesium sulfate, pH 5.5 at 25 degrees C. Analysis of TNF by isoelectric focusing under native and denaturing conditions indicates that TNF molecules exist as trimers in solution.
  • (13) In the presence of 1% phenol, 1.0 M sodium chloride, and at a pH of 8.5, a rhombohedral form is produced with two monomers in the asymmetric unit, space group R3, a = 79.92 A and c = 40.39 A.
  • (14) Mg-containing calcium phosphate crystals including pseudocuboidal, rhombohedral shapes and groupings of quadrangular blades cubically arranged were found in human tooth enamel by scanning electron microscopy and by electron probe microanalysis.
  • (15) The hydrolytic cleavage of the peptide backbone takes place only in preparations containing rhombohedral crystals in addition to free zinc ions.
  • (16) The size measured corresponds to an aggregate of trimers making a unit rhombohedral cell consistent with x-ray crystallographic data (McPherson, A.
  • (17) C43, 1653-1655] is properly described as rhombohedral, space group R3c, with a = 12.355 (4) A, a = 51.01 (2) degrees, Z = 2.
  • (18) Crystals and rhombohedral aggregates of calcite, aggregates of small crystals and tabular crystals of vaterite and fibrous radial aggregates in the form of ooliths were found.
  • (19) Some otoconia are exceptions, evidently seeding and growing in the pure rhombohedral form.
  • (20) The second crystal form is rhombohedral with dimensions unit cell a = 121.1 A, alpha = 60 degrees, space group R32 and diffracts to a resolution of 3.5 A.

Triclinic


Definition:

  • (a.) Having, or characterized by, three unequal axes intersecting at oblique angles. See the Note under crystallization.

Example Sentences:

  • (1) Comparison with earlier neutron studies on triclinic lysozyme showed that neither the molecular structure nor the thermal motions were affected significantly by the ethanol.
  • (2) Crystals of azimexon are triclinic, space group P1, with a = 6.342(2), b = 6.804(1), c = 13.106(2) A, alpha = 75.17(1), beta = 89.17(2), gamma = 83.26(2) degrees, V = 542.8 A3, Z = 2, D0 = 1.18 g cm-3 and Dc = 1.189 g cm-3.
  • (3) Pure monoclinic or triclinic calcium pyrophosphate dihydrate (CPPD) crystals, apatite crystals or mixtures of these crystals were injected into the synovial-like space created by the rat air pouch to compare the acute inflammation induced by these crystals.
  • (4) It is suggested that distortion in the hexagonal lattice below the pretransition temperature previously reported by X-ray diffraction techniques may be responsible for interchain interactions which give rise to a Raman band observed only in the triclinic lattice of even-numbered n-alkanes.
  • (5) Methyl [4aS*-(4 alpha,4a beta,7 beta,13b beta,14a beta)]-7,8,13,13b,14,14a- hexahydro-4-methyl-5-oxo-4H-indolo-[2,3-a]pyrano[3,4-g]qu inolizine-7-carboxylate acetone solvate, C22H22N2O4.C3H6O, Mr = 424.50, triclinic, P1, a = 9.9955(13), b = 10.8523(14), c = 11.9352(14) A, alpha = 63.189(9), beta = 72.286(9), gamma = 72.901(10) degrees, V = 1081.8(2) A3, Z = 2, Dx = 1.30 g cm-3(198K), mu = 0.8554 cm-1, Mo K alpha radiation, lambda = 0.7107 A, F(000) = 452, T = 198 K, R = 0.0435 for 3842 reflections, FO greater than or equal to 4 sigma (FO).
  • (6) A large number of epitaxially dimensional matches between MSU and triclinic (t) and monoclinic (m) CPPD were identified, suggesting that MSU crystals can epitaxially induce CPPD crystal growth.
  • (7) The second form crystallizes in the triclinic space group P1, with unit cell dimensions a = 134.0 A, b = 144.7 A, c = 98.6 A, alpha = 90.30 degrees, beta = 97.1 degrees, gamma = 90.20 degrees, consistent with the presence of 10 to 12 molecules of the complex in the unit cell.
  • (8) (1) (2S,3R,4R,6R)-3,4-O-Carbonyl-7,7-dimethylenedithio-2,4,6-trimet hylnonane-1,3,4-triol, C15H26O4S2, M(r) = 334.49, triclinic, P1, a = 6.460 (2), b = 8.917 (3), c = 15.616 (5) A, alpha = 83.60 (3), beta = 83.41 (2), gamma = 89.52 (2) degrees, V = 888.0 (5) A3, Z = 2, Dx = 1.25 g cm-3, mu = 2.980 cm-1, lambda (Mo K alpha) = 0.7107 A, F(000) = 360, T = 298 K, R = 0.0465 for 1832 reflections [Fo greater than or equal to 4 sigma (Fo)].
  • (9) Oriented films of the sodium salt of heparin crystallize in a triclinic unit cell.
  • (10) N-(tert-Butylcarbonylglycylaminoethyl)-N-(ethyl)ammonium tetraphenylborate, C11H24N3O+2.C24H20B-, Mr = 549.57, triclinic, P-1, a = 11.567 (2), b = 11.922 (2), c = 14.484 (3) A, alpha = 70.99 (2), beta = 74.83 (2), gamma = 59.33 (1) degrees, V = 1613.1 A3, Z = 2, D chi = 1.13 g cm-3, lambda(Cu K alpha) = 1.5418 A, mu = 4.69 cm-1, mu Rmax much less than 1, F(000) = 592, T = 293 K, R = 0.058 for 3491 observed reflections.
  • (11) 4Li+.C14H4O8(4-).12H2O, M(r) = 544.18, triclinic, P1, a = 9.608 (2), b = 10.034 (2), c = 7.033 (1) A, alpha = 94.29 (1), beta = 96.95 (1), gamma = 64.52 (1) degree, V = 607.4 (2) A3, Z = 1, D chi = 1.49 g cm-3, lambda (Mo K alpha) = 0.71073 A, mu = 1.29 cm-1, T = 295 K, F(000) = 284, R = 0.039 for 2781 unique reflections having I greater than sigma I.
  • (12) [Rh2(C2H3O2)4(C11H16N5O4)2].H2O, Mr = 1024.6, triclinic, P1, a = 7.808 (3), b = 11.469 (4), c = 12.091 (2) A, alpha = 69.55 (2), beta = 79.46 (2), gamma = 76.61 (3) degrees, V = 980.7 (6) A3, Z = 1, Dx = 1.735 g cm-3, lambda (Cu K alpha) = 1.5418 A, mu = 77.6 cm-1, F(000) = 522, room temperature, R = 0.053 for 3638 unique reflections.
  • (13) The crystals are triclinic, space group P1, with two protein molecules in the unit cell; unit cell parameters are a = 55.8 A, b = 40.1 A, c = 33.7 A, alpha = 90.0 degrees, beta = 109.3 degrees, gamma = 93.2 degrees.
  • (14) Two related crystal forms have been obtained, one triclinic, and one tetragonal, both with one toxin molecule per asymmetric unit.
  • (15) Synthetic triclinic calcium pyrophosphate dihydrate crystals were uniformly trace-labeled with Ytterbium-169 (169Yb), a pure gamma-emitting isotope with a halflife of 31 days.
  • (16) The presence of both ferrous and ferric ions resulted in the more rapid formation of the two crystals observed in vivo, triclinic CPPD and monoclinic CPPD.
  • (17) Cross-linked triclinic lysozyme was denatured with sodium dodecyl sulfate.
  • (18) Following dissolution of the triclinic crystals, the second crystal form also grew at 277 K but remained stable even at room temperature.
  • (19) One hundred and ten kinds of reciprocal lattice planes of the triclinic calcium pyrophosphate dihydrate (CPPD) crystal were made from its crystallographical data.
  • (20) C18H16Cl3NO, Mr = 368.69, triclinic, P1-, a = 10.360 (1), b = 10.397 (1), c = 10.810 (2) A, alpha = 60.84 (1), beta = 57.22 (1), gamma = 70.97 (1) degrees, V = 852 (1) A3, Z = 2, Dx = 1.437 Mg m-3, Mo K alpha radiation, lambda = 0.71073 A, mu = 0.54 mm-1, F(000) = 380, T = 293 (1) K, R = 0.0287 for 2330 observed reflections with I greater than 3 sigma (I).