Constant data like element masses are provided as CSV-file and gets compiled on build time (see: build.rs). * Amino acid data is used from: https://proteomicsresource.washington.edu/protocols06/masses.php * Elements data is used from: https://proteomicsresource.washington.edu/protocols06/masses.php * Subatomic particles data is used from en.wikipedia.org/wiki/(Proton|Electron|Neutron) (need better source)