Smooth Mach Dynamics -- Smooth Particle Hydrodynamics for solids and fluids Currently, the package has the following features: Does liquids via traditional Smooth Particle Hydrodynamics (SPH) Also solves solids mechanics problems via a state of the art stabilized meshless method with hourglass control. Can specify hydrostatic interactions independently from material strength models, i.e. pressure and deviatoric stresses are separated. Many material models available (Johnson-Cook, plasticity with hardening, Mie-Grueneisen, Polynomial EOS). Easy to add new material models. Rigid boundary conditions (walls) can be loaded as surface geometries from *.STL files. See the file doc/PDF/SMD_LAMMPS_userguide.pdf to get started. There are example scripts for using this package in examples/USER/smd. The person who created this package is Georg Ganzenmuller at the Fraunhofer-Institute for High-Speed Dynamics, Ernst Mach Institute in Germany (georg.ganzenmueller at emi.fhg.de). Contact him directly if you have questions.