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H centered cell

The H centered cell (triple hexagonal cell) is an alternative description of the hexagonal Bravais lattice. From the conventional hP cell one obtains the hH cell by taking the new basis vectors by means of one of the following transformation matrices, which give three possible orientations of the hH cell with respect to the hP cell:

H1: 110/-120/001 H2: 2-10/110/001 H3: 1-20/2-10/001

The resulting hH cell has centering nodes at 1/3,2/3,0 and 2/3,1/3,0.

Secondary and tertiary elements in the hP cell are exchanged in the hH cell. For  example , the space-group symbol P3m1 become H31m when the triple cell is used.

See also

  • Section 4.3.5.3 in the International Tables for Crystallography, Volume A
  • Chapter 5 in the International Tables for Crystallography, Volume A