  Single crystals have high atomic electric fields as much as 10^{11} V/m,
which correspond to magnetic fields of \sim 10^3 T. These fields can be
utilized to convert X rays into Axion Like Particles (ALPs) coherently similar
to X-ray diffraction. In this paper, we perform the first theoretical
calculation of the Laue-case conversion in crystals based on the Darwin
dynamical theory of X-ray diffraction. The calculation shows that the Laue-case
conversion has longer interaction length than the Bragg case, and that ALPs in
the keV range can be resonantly converted by tuning an incident angle of X
rays. ALPs with mass up to O(10 keV) can be searched by
Light-Shining-through-a-Wall (LSW) experiments at synchrotron X-ray facilities.
