T - IfB

Molecular Dynamicsgeneralized coordinates with α degrees of freedomof particle i:N particles:Hamiltonianq q q p p p Q( q ,..., q ) , P( p ,..., p )1 1 i( i,..., i) ,i( i,..., i)1 N1H ( P, Q) K( P) V( Q)kinetic energy:K( P) m i is mass of particle i.k p 2i2mi k1iN3Potential energyMake expansion of potential energy VQ ( ) v( q) v( q, q) v( q, q, q) ...1 i 2 i j 3 i j ki i ji i ji kjTypically three or more body interactionsare neglected and their effect considered inan effective two body interactioneff attr rep v2 ( q , q ) v ( r) v ( r) , r q qi j i jattractiverepulsive4