The fractal dimension of a surface allows its degree of roughness to be characterized quantitatively. However, limited effort is attempted to calculate the fractal dimension of surfaces computed from precisely known atomic coordinates from computational biomolecular and nanomaterial studies. This work proposes methods to estimate the fractal dimension of the surface of any 3D object composed of spheres, by representing the surface as either a voxelized point cloud or a mathematically exact surface, and computing its box-counting dimension. Sphractal is published as a Python package that provides these functionalities, and its utility is demonstrated on a set of simulated palladium nanoparticle data.

翻译：表面的分形维数能够定量表征其粗糙程度。然而，目前仅有少量研究尝试计算计算生物分子和纳米材料研究中已知精确原子坐标所生成表面的分形维数。本文提出了一种估计由球体构成的任意三维物体表面分形维数的方法，通过将表面表示为体素化点云或数学上的精确表面，并计算其计盒维数。Sphractal以Python包形式发布，提供了上述功能，并通过一组模拟钯纳米颗粒数据展示了其应用价值。