1 / 19

Point Groups (Crystal Classes)

Point Groups (Crystal Classes). Stereographic Projections. Used to display crystal morphology. X for upper hemisphere. O for lower. Stereographic Projections. We will use stereographic projections to plot the perpendicular to a general face and its symmetry equivalents (general form hkl ).

keene
Download Presentation

Point Groups (Crystal Classes)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Point Groups(Crystal Classes)

  2. Stereographic Projections • Used to display crystal morphology. • X for upper hemisphere. • O for lower.

  3. Stereographic Projections • We will use stereographic projections to plot the perpendicular to a general face and its symmetry equivalents (general form hkl). • Illustrated above are the stereographic projections for Triclinic point groups 1 and -1.

  4. 32 PointGroups:Hermann-Mauguin Symbols • Three positions in H-M symbol • Triclinic: No unique axis Only 1 or -1 • Monoclinic: [010] • Orthorhombic: [100], [010], [001] • Tetragonal: [001], [100], [110] • Trigonal: [001], [100], • Hexagonal: [001], [100], [210] • Cubic: [100], [111], [110]

  5. 32 PointGroups (Crystal Classes) • Triclinic: 1, 1 • Monoclinic: 2, 2=m, 2/m • Orthorhombic: 222, 2mm, 2/m2/m2/m (=mmm) • Tetragonal: 4, 4, 4/m, 42m, 422 4mm 4/m2/m2/m • Trigonal: 3, 3m, 32, 3, 32/m • Hexagonal: 6, 6, 6/m, 6m2, 622, 6mm, 6/m2/m2/m • Cubic: 23, 2/m3, 432, 43m, 4/m32/m

  6. Triclinic System

  7. Monoclinic System

  8. Orthorhombic System

  9. Trigonal System

  10. Trigonal System

  11. Tetragonal System

  12. Tetragonal System

  13. Tetragonal System

  14. Hexagonal System

  15. Hexagonal System

  16. Hexagonal System

  17. Cubic System

  18. Cubic System

  19. 32 PointGroups (Crystal Classes) • Triclinic: 1, 1 • Monoclinic: 2, 2=m, 2/m • Orthorhombic: 222, 2mm, 2/m2/m2/m (=mmm) • Tetragonal: 4, 4, 4/m, 42m, 422 4mm 4/m2/m2/m • Trigonal: 3, 3m, 32, 3, 32/m • Hexagonal: 6, 6, 6/m, 6m2, 622, 6mm, 6/m2/m2/m • Cubic: 23, 2/m3, 432, 43m, 4/m32/m

More Related