The higher second??harmonic efficiency, in powder, of a new organic molecular crystal N??(4?? nitrophenyl)??(L)??prolinol (NPP) is reported. Electronic polarizability of NPP molecules relates to that of other para??nitroaniline??like structures such as that of previously reported N?? (2, 4??dinitrophenyl) methyl alaninate (MAP), and the increase in crystalline nonlinear efficiency by one order of magnitude above the latter is ascribed to an ''optimized'' ...
