Dear Elk Developers, I am a teacher and researcher and I have created two modified versions of Elk 3.3.17: elkpdg - a pedagogical copy designed to teach ab initio calculations step by step, using 3 simplified input files. elkader - a research-oriented modification with 3 input files and two Python scripts: one that merges the 3 input files into a standard elk.in, and another that converts all numerical parameters into human-readable form. The algorithms and input file structure are my own design....