DynHeMat: A program with phenomenological inclusion of superfluidity in molecular dynamics simulations of helium nanodroplets
Description
One major shortcoming of classical and mixed quantum-classical approaches devoted to large helium nanodroplets (HNDs) is the lack of superfluidity. A method, recently published in Chemical Physics Letters, is implemented in DynHeMat to enable the user to take into account helium superfluidity on a phenomenological manner by imposing projectiles colliding with HNDs to maintain their velocity at the critical Landau velocity when they move within the HND. Projectiles can thus enter deeply inside the droplet and, for instance, the stability of weakly-bound complexes in helium can be investigated. Moreover, the database provided with DynHeMat, called ZPAD_DB, contains a new file with the positions and velocities of He_70000 equilibrated at T = 0.37 K for 1.5 ns with the mPL He-He pseudopotential. Output files collecting the HND center-of-mass position and linear momentum as well as the HND total angular momentum are supplied for each trajectory and output files gathering energetic data are somewhat changed. Finally, a few error messages displayed at DynHeMat execution are slightly modified.