Convert from X unit to legua

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.

Unit Definition (legua)
nit of area used in the southwest US, equal to 25 labors, or 4428 acres (Texas), or 4439 acres (California). Also, a unit of length-- approximately three miles.