Effective conservation of energy and momentum algorithm using switching potentials suitable.pdf

7 0 Effective conservation of energy and momentum 0 2 algorithm using switching potentials suitable for r p molecular dynamics simulation of A 4 thermodynamical systems ] Christopher G. Jesudason ∗ h p Laboratory of Physics and Helsinki Institute of Physics, - p P.O.Box 1100, FIN-02015 HUT, Finland. m Email: jesu@.my, chrysostomg@ o c 4 April, 2007 . s c i s Abstract y h During a crossover via a switching mechanism from one 2-body poten- p tial to another as might be applied in modeling (chemical) reactions in [ the vicinity of bond formation, energy violations would occur due to finite step size which determines the trajectory of the particles relative to the 1 potential interactions of the unbonded state by numerical (e.g. Verlet) v integration. This problem is overcome by an algorithm which preserves 6 the coordinates of the system for each move, but corrects for energy dis- 5 5 crepancies by ensuring both energy and momentum conservation in the 0 dynamics. The algorithm is tested for a hysteresis loop reaction model . with an without the implementation of the algorithm. The tests involve 4 checking the