/usr/include/OpenMS/CHEMISTRY/ is in libopenms-dev 1.11.1-5.
This file is owned by root:root, with mode 0o755.
..
/usr/include/OpenMS/CHEMISTRY/AAIndex.h
/usr/include/OpenMS/CHEMISTRY/AASequence.h
/usr/include/OpenMS/CHEMISTRY/EdwardsLippertIterator.h
/usr/include/OpenMS/CHEMISTRY/EdwardsLippertIteratorTryptic.h
/usr/include/OpenMS/CHEMISTRY/Element.h
/usr/include/OpenMS/CHEMISTRY/ElementDB.h
/usr/include/OpenMS/CHEMISTRY/EmpiricalFormula.h
/usr/include/OpenMS/CHEMISTRY/EnzymaticDigestion.h
/usr/include/OpenMS/CHEMISTRY/IsotopeDistribution.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/IMSAlphabet.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/IMSAlphabetParser.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/IMSAlphabetTextParser.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/IMSElement.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/IMSIsotopeDistribution.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/IntegerMassDecomposer.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/MassDecomposer.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/RealMassDecomposer.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/Weights.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/sources.cmake
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/MassDecomposition.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/MassDecompositionAlgorithm.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/sources.cmake
/usr/include/OpenMS/CHEMISTRY/ModificationDefinition.h
/usr/include/OpenMS/CHEMISTRY/ModificationDefinitionsSet.h
/usr/include/OpenMS/CHEMISTRY/ModificationsDB.h
/usr/include/OpenMS/CHEMISTRY/ModifierRep.h
/usr/include/OpenMS/CHEMISTRY/PepIterator.h
/usr/include/OpenMS/CHEMISTRY/Residue.h
/usr/include/OpenMS/CHEMISTRY/ResidueDB.h
/usr/include/OpenMS/CHEMISTRY/ResidueModification.h
/usr/include/OpenMS/CHEMISTRY/SvmTheoreticalSpectrumGenerator.h
/usr/include/OpenMS/CHEMISTRY/SvmTheoreticalSpectrumGeneratorSet.h
/usr/include/OpenMS/CHEMISTRY/SvmTheoreticalSpectrumGeneratorTrainer.h
/usr/include/OpenMS/CHEMISTRY/TheoreticalSpectrumGenerator.h
/usr/include/OpenMS/CHEMISTRY/TrypticIterator.h
/usr/include/OpenMS/CHEMISTRY/WeightWrapper.h
/usr/include/OpenMS/CHEMISTRY/sources.cmake