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单斜晶体NaH_3(SeO_3)_2的晶胞参数为α=5.90(?),b=4.82(?),c=10.19(?),β=91°20′。晶胞中含有2{NaH_3(SeO_3)_2}。密度的计算值和观测值各为3.22_4和3.21±0.01克/厘米~3。根据系统消光,晶体结构中存在着滑移面n。最后根据全部原子的坐标值肯定晶体的空间群为C_3~2—Pn。 根据Weissenberg图hOl上各衍射点的分布情况,可为结构在(010)面上的投影引出一个a′=5.94(?),b′=5.90(?),γ′=119°50′的假六方单位,投影的假二维空间群为p6m。假六方单位的a′=1/2(c-α),b′=α如图1中所示。Patterson投影P(u,w)肯定了图1中Se和Na原子的x,z坐标,而P(v,w)给出了它们的y坐标。从这些坐标值看来,晶体中的Se和Na原子系按空间群C_(2h)~5-P2_1/n分布。依靠上述重原子的坐标值并按空间群C_2h~5计算了电子密度分布函数ρ(x,z)和ρ(y,z)。计算结果指出,晶胞中的O原子系按空间群C_3~2分布。最后按空间群C_3~2对上述电子密度分布函数逐步进行修改,使O原子有了明确的表现,并取得了图2和图3中的结果。晶胞中各原子的坐标值按空间群C_3~2列于表2中。晶体结构示出于图4中。 晶体中三角锥形的分子SeO(OH)_2和离子[SeO_2(OH)]各相当于对称结构式 其中Se—OH=1.75—1.82(?),Se=O=1.66—1.69(?)(图5)。分子SeO(OH)_2和离子[SeO_2(
The unit cell parameters of monoclinic NaH 3 (SeO 3) 2 are α = 5.90 (?), B = 4.82 (?), C = 10.19 (?) And? = 9120 °. The unit cell contains 2 {NaH_3 (SeO_3) _2}. The calculated and observed density values were 3.22_4 and 3.21 ± 0.01 g / cm3, respectively. According to the system extinction, the crystal structure exists in the sliding surface n. At last, the space group of crystal is confirmed as C_3 ~ 2-Pn according to the coordinates of all the atoms. According to the distribution of each diffraction point on hOl of Weissenberg, a projection of a ’= 5.94 (?), B’ = 5.90 (?) And γ ’= 119 ° 50’ can be derived for the projection of the structure on the (010) Six-party unit, the projected fake two-dimensional space group p6m. A ’= 1/2 (c-α) for a fake hexa unit, b’ = α as shown in FIG. 1. The Patterson projection P (u, w) affirms the x, z coordinates of the Se and Na atoms in Figure 1, while P (v, w) gives their y-coordinates. Seen from these coordinate values, the Se and Na atoms in the crystal are distributed in the space group C_ (2h) ~ 5-P2_1 / n. The electron density distribution functions ρ (x, z) and ρ (y, z) are calculated on the basis of the coordinate values of the heavy atoms and space group C_2h ~ 5. The calculation results show that O atoms in unit cell are distributed by space group C_3 ~ 2. Finally, according to the space group C_3 ~ 2, the above electronic density distribution function is modified step by step so that the O atom has a definite performance, and the results in FIGS. 2 and 3 are obtained. The coordinates of each atom in the unit cell are listed in Table 2 according to the space group C_3 ~ 2. The crystal structure is shown in FIG. 4. The triangular conical molecule SeO (OH) 2 and the ion [SeO 2 (OH)] in the crystal each correspond to the symmetrical structure formula, where Se = OH = 1.75-1.82 (?), Se = O = 1.66-1.69 ). Molecular SeO (OH) _2 and ions [SeO_2 (