Wuttke Joachim
Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenbergstrasse 1, 85748 Garching, Germany.
J Appl Crystallogr. 2021 Mar 25;54(Pt 2):580-587. doi: 10.1107/S1600576721001710. eCollection 2021 Apr 1.
Coordinate-free expressions for the form factors of arbitrary polygons and polyhedra are derived using the divergence theorem and Stokes's theorem. Apparent singularities, all removable, are discussed in detail. Cancellation near the singularities causes a loss of precision that can be avoided by using series expansions. An important application domain is small-angle scattering by nanocrystals.
利用散度定理和斯托克斯定理推导出任意多边形和多面体形状因子的无坐标表达式。详细讨论了所有可消除的表观奇点。奇点附近的抵消会导致精度损失,可通过使用级数展开来避免。一个重要的应用领域是纳米晶体的小角散射。