/usr/include/palabos/finiteDifference/ is in libplb-dev 1.5~r1+repack1-3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/palabos/finiteDifference/fdFunctional2D.h
/usr/include/palabos/finiteDifference/fdFunctional2D.hh
/usr/include/palabos/finiteDifference/fdFunctional3D.h
/usr/include/palabos/finiteDifference/fdFunctional3D.hh
/usr/include/palabos/finiteDifference/fdStencils1D.h
/usr/include/palabos/finiteDifference/fdStencils2D.h
/usr/include/palabos/finiteDifference/fdWrapper2D.h
/usr/include/palabos/finiteDifference/fdWrapper2D.hh
/usr/include/palabos/finiteDifference/fdWrapper3D.h
/usr/include/palabos/finiteDifference/fdWrapper3D.hh
/usr/include/palabos/finiteDifference/finiteDifference2D.h
/usr/include/palabos/finiteDifference/finiteDifference3D.h
/usr/include/palabos/finiteDifference/headers2D.h
/usr/include/palabos/finiteDifference/headers2D.hh
/usr/include/palabos/finiteDifference/headers3D.h
/usr/include/palabos/finiteDifference/headers3D.hh
/usr/include/palabos/finiteDifference/interpolations2D.h
/usr/include/palabos/finiteDifference/interpolations2D.hh
/usr/include/palabos/finiteDifference/interpolations3D.h
/usr/include/palabos/finiteDifference/interpolations3D.hh