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Core CIF Dictionary version 2.3

_cell_reciprocal_angle_

Names

'_cell_reciprocal_angle_alpha' '_cell_reciprocal_angle_beta' '_cell_reciprocal_angle_gamma'

Category: cell

Data type: numb (with optional s.u. in parentheses)

Enumeration range: 0.0 -> 180.0
Enumeration default: 90.0

Units: deg ( degrees)

Definition

    	
   The angles defining the reciprocal cell.  These are related to 
   those in the real cell by:

   cos(recip-alpha)
       = [cos(beta)*cos(gamma) - cos(alpha)]/[sin(beta)*sin(gamma)]

   cos(recip-beta)
       = [cos(gamma)*cos(alpha) - cos(beta)]/[sin(gamma)*sin(alpha)]

   cos(recip-gamma)
       = [cos(alpha)*cos(beta) - cos(gamma)]/[sin(alpha)*sin(beta)]

   Ref: Buerger, M.J. (1942). X-ray Crystallography, p. 360.
           New York: John Wiley & Sons Inc.
 


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