POSITIONS OF THE PROTONS IN POTASSIUM TET RAAMIDOZINCATE, K2ZN(NH2)(4)

X-ray single crystal data for K2Zn(NH2)(4) allowed the determination o f the so far unknown positions of the protons: <P(1)over bar>, Z=2, a= 6.730(1) Angstrom, b=7.438(1) Angstrom, c=8.019(2) Angstrom, alpha=72. 03(2)degrees, beta=84.45(2)degrees, gamma=63.82(1)degrees, Z(F-o) with (F-o)(2) greater than or equal to 3 sigma(F-o)(2)=2166, Z(parameters) =96, R/R-w=0.032/0.039. In the structure of K2Zn(NH2)(2) the amide ion s are nearly hexagonal close packed. One layer of octahedral holes par alIel to (010) is fully occupied by potassium atoms and zinc is in an ordered way in a quarter of the tetrahedral holes of the next layer. T he orientation of the protons of the amide ions is characteristic for this type of structure (filled up CdI2 type).