【摘要】 Nd₂O₃·BaO·Al₂O₃·6B₂O,晶体属六方晶体系,空间群为D_h-P62m晶胞参数a=4.566（2）A.Z=24.92（1）A,Z=1。由PW1100四园衍射仪收集到1460个独立衍射强度,用SNELX-76程序中的直接法解得晶体结构,全矩阵最小二乘方法修正结构参数,最后得到偏离因子R=8.80％（未校正吸收）,全部计算在SORDCP/M-68K微处理机上完成,晶胞中2/3的B原于位于四面体内,形成[B₂O₅]⁴-团,另外1/3的B原子,连结33个O原子形成[B₂O₃]中性团。由对称面联系的[B₂O₃]团的B与B原子之间借助范德华键键合,结构上的这一特点,与硼酸铝钡钕晶体垂直C轴方向有明显解理性质完成一致。这一晶体的结构式可表示为Nd₂BaAl₂O_1-x[B₂O₅]₄[B₄O_{4+x+（2-x）}]更多还原

【Abstract】 The crystal structure of Nd2O3·BaO·Al2O3·6B2O3 is hexagonal system, space group D33h-P62m with Z=1 and cell parameters a = 4.566(2)A , c = 24.92(1)A. The intensity data of 1460 independent reflections were obtained by using PW 1100 four-circle diffractometer. The crystal structure was determined by direct method with SHELX-76 program system and refined by full matrix least-squares technique to R-value of 8.80% for 1074 observable reflections. All calculations were carried out on miniproc essor of SORD CP/M-68K. Two-thirds of B atoms in unit cell sat in tetrahe-dral coordination makes the formula of bornate radical [B2O5]4- the other one-third of B atoms makes neutral group of [B2O3]0 which links with other cations by Van der Waals bond. The obvious cleavage of Nd2O3·BaO·Al2O3·6B2O3 crystal perpendicular to c-axis can be explained by this structure characteristic. The structure formula of this crystal can be described by Nd2BaAl2O1-x[B2O5]4[B4O4+z+(2-x)].更多还原