In this repository, an Abaqus Python scripting approach for a natural frequency analysis of an auxetic lattice structure is presented. The script "Modal_4x4x4_Lattice.py" produces an input file for Abaqus that controls all necessary preprocessing and simulation steps. Additionally, for the first step of postprocessing, all needed results are extracted from the previously generated odb-file and written to a text file. This text file is then used by the script "Calculation_Deformation_Matrix.py" to calculate the deformation matrix N of each individual unit cell.