The reciprocal cell length (recip-c) in inverse Angstroms.
(recip-a), (recip-b) and (recip-c) are related to the real cell
by the following equation:
recip-a = b*c*sin(alpha)/V
recip-b = c*a*sin(beta)/V
recip-c = a*b*sin(gamma)/V
where V is the cell volume.
Ref: Buerger, M. J. (1942). X-ray Crystallography, p. 360.
New York: John Wiley & Sons Inc.