Langevin dynamics implementation

[SHervoe-Hansen]

The implementation of Langevin dynamics in Faunus for a Lennard-Jones fluid/gas is well underway in my fork of Faunus. Checklist which should preferably be handled as separate PRs:

• [x] Working example of LJ system
• [ ] Unit testing
  • simple LJ system. RDF, temperature, avg. kinetic and potential energy? Compare w. MC
  • harmonic oscillator?
• [ ] Force calculation implementation:

  • 284: Reciprocal ewald space

  • 283: Bonded interactions (harmonic, torsion, dihedrals -- see OpenMM implementation) and also Allen+Tildesley, Appendix C

  • FunctorPotential for combined potentials
  • Anisotropic non-bonded interactions?
  • See Allen and Tildesley's Appendix C as well as their Github rep with examples of force calculations (ewald, angles, dipoles etc.)
• [ ] Error handling
  • [ ] Gracefully exit from explosion (closes #305)
• [ ] Documentation (moves.md)
• [ ] An initialisation scheme for simulation of liquids (slow heating, minimisation using 0 K Monte Carlo).
• [ ] Improved control over MD/MC switching.
• [ ] Parallel scheme for force calculation in Nonbonded class (OMP pragmas?)

[udayardahal]

Is it possible for me to get the beta version of the code where you have implemented langevin dynamics? I want to test CG martini system ( I don't have any angle/dihedral terms in the system). Thanks,