http://jp-minerals.org/vesta/jp/
Useful to draw crystal structure.
"Output vector image" function seems not working now. Use "output laster image" function and convert the laster image to pdf using "convert to Adobe PDF" function by right-clicking on the file.
https://automeris.io/WebPlotDigitizer/
"It is often necessary to reverse engineer images of data visualizations to extract the underlying numerical data. WebPlotDigitizer is a semi-automated tool that makes this process extremely easy: " -from the WebPlotDigitizer web site-