KLiSO4(C66)结构中Li原子位置的测定

Bradley在1925年所定出KLiSO₄室温相的结构为(C₆⁶),但其中的Li原子位置并非测定的,而是推断为在三次轴上有较大的空隙处。这一位置与晶体学一般成键理论的认识是有矛眉的,因而最近有人提出了异议。我们重新测定了这一晶体结构,特别是实测了Li原子的位置。新定出的KLiSO₄晶体结构中的Li原子位置是:x=1/3,y=2/3,z=0.1797(16)。而Bradley所推断的Li原子位置是:x=1/3,y=2/3,z=0.3488。前者与文献8]中估算值相接近。新定出的Li原子位置与近邻O原子构成了键长约在1.9A左右的Li—O四面体。 关键词：

DETERMINING THE POSITION OF LITHIUM ATOM IN LITHIUM POTASSIUM SULPHATE (C66)

The structure of KLiSO₄ at room temp erature was determined (C₆⁶) in 1925 by Bradley. The position of Li atom at the void on a triad was inferred but not measured. This result is in contradiction with the general theory of chemical bonding, so, recently, Meng and Cao presented a view disagreeing with it.We have redetermined the structure of KLiSO₄, in particular the position of Li atom. New result shows that Li atom is located at x=1/3, y=2/3, z=0.1797(16) instead of x=1/3, y=2/3, z=0.3488 as described by Bradley. The former is roughly the same as that predicted by steric considerations in ref. 8]. Four nearest O atoms around Li atom form a tetrahedroid.