Convert from alen [Danish] to X unit

Unit Definition (alen [Danish])
The Danish Alen (also used in Norway) is slightly longer than the Scandinavian Alen. It is just longer than two feet and more precisely equal to 62.77 centimeters (24.71 inches).

Unit Definition (X unit)
The X-unit (symbol xu) is a unit of length formerly used to measure the wavelength of X-rays and gamma rays. The X-unit is approximately 1.0021×10-13 metre. Defined by the Swedish physicist Karl Manne Georg Siegbahn (1886-1978) in 1925, the X-unit could not at that time be measured directly; the definition was instead made in terms of the spacing between planes of the calcite crystals used in the measuring apparatus.