Crystal Lattice Structures:	Creation Date: 10 Apr 2002
	Last Modified: 21 Oct 2004

The βSe (A_l) Structure

You can now

• see the structure from several perspectives;
• examine the structure with an external viewer; or
• download the coordinates of the atoms in these pictures in XYZ format.
• visualize the structure (Uses the JMOL Applet)

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• Donohue refers to this as the ``monoclinic β'' Se structure.
• The atoms sit on 8 distinct (4e) sites in the monoclinic P2₁/c lattice. Each set of sites has its own structural parameters. We therefore list only one set of sites.
• We've corrected a mistake in the z coordinates of the 2^nd and 4^th atoms of each set.

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• Prototype: βSe
• Pearson Symbol: mP32
• Strukturbericht Designation: A_l
• Space Group: P2₁/c (Cartesian and lattice coordinate listings available)
• Number: 14
• Reference: Donohue, Structures of the Elements, pp. 379-84.
• Other Systems with this Structure: S₂Si
• Primitive Vectors:

  A1	=	a X
  A2	=	b Y
  A3	=	c cos(β) X + c sin(β) Z

• Basis Vectors:
  

  B4n-3	=	+ xnA1 + ynA2 + znA3	=	+ [xn a + zn c cos(β)]X + yn bY + zn c sin(β)Z	(Se-n)	(4e)
  B4n-2	=	+ xnA1 + (½ - yn)A2 + (½ + zn)A3	=	+ [xn a + (½ + zn) c cos(β)]X + (½ - yn) bY + (½ + zn) c sin(β)Z	(Se-n)	(4e)
  B4n-1	=	- xnA1 - ynA2 - znA3	=	- [xn a + zn c cos(β)]X - ynb Y - zn c sin(β)Z	(Se-n)	(4e)
  B4n	=	- xnA1 + (½ + yn)A2 + (½ - zn)A3	=	- [xn a - (½ - zn) c cos(β)]X + (½ + yn) bY + (½ - zn) c sin(β)Z	(Se-n)	(4e)

  
  where n = 1,2,3,...,8.
  

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Structures indexed by: Strukturbericht Symbol Pearson Symbol Space Group Prototype

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