Shrager R I, Shmueli U, Weiss G H
Physical Sciences Laboratory, Division of Computer Research and Technology, National Institutes of Health, Bethesda, Maryland 20982.
Acta Crystallogr A. 1994 Sep 1;50 ( Pt 5):633-6. doi: 10.1107/s0108767394002382.
A new approximate method of computing the conditional probability density function (c.p.d.f.) of a three-phase invariant is investigated, the results being compared to accurate calculations [Shmueli, Rabinovich & Weiss (1989). Acta Cryst. A45, 361-367]. A direct dependence on N, the number of atoms in the unit cell, is incorporated into the new approximation and its performance in the equal-atom case appears to be excellent over a large range of N values. The polynomial approximation of the recently published method [Posner, Shmueli & Weiss (1993). Acta Cryst. A49, 260-265] has been improved in both accuracy and range.
研究了一种计算三相不变量条件概率密度函数（c.p.d.f.）的新近似方法，并将结果与精确计算结果进行了比较[什穆埃利、拉比诺维奇和魏斯（1989年）。《晶体学报》A45卷，361 - 367页]。新近似方法中纳入了对单位晶胞中原子数N的直接依赖关系，并且在等原子情况下，其在大范围的N值上表现出色。最近发表的方法[波斯纳、什穆埃利和魏斯（1993年）。《晶体学报》A49卷，260 - 265页]的多项式近似在精度和范围上都得到了改进。
