Crystal growth, crystal structure and linear optical properties of the non-centrosymmetric ammonium bis(nitrilotriacetato)zirconate and hafnate, (NH4)(2)[Zr{N(CH2COO)(3)}(2)] and (NH4)(2)[Hf{N(CH2COO)(3)}(2)]

Large single crystals of ammonium bis(nitrilotriacetato)zirconate, (NH4)(2) [Zr{N(CH2COO)(3)}(2)] (to be written (NH4)(2)[Zr(NTA)(2)]), were grown. Lin ear optical properties were measured (indices of refraction and transparenc y range) and the phase matching conditions for second harmonic generation p rocess were determined. Crystal structures of the zirconate and the isomorp hic hafnate were solved from single crystal X-ray diffraction data (P3(1,2) 21; Z = 3; Zr: a = 9.582(1) Angstrom, c = 16.611(4) Angstrom, Hf: a = 9.584 6(5) Angstrom, c = 16.5920(8) Angstrom) and the geometry of the complex gro ups [Zr(NTA)(2)](2-) and [Hf(NTA)(2)](2-) was analysed.