T - IfB

TricksMost time consuming loop is calculation of forcebecause one must consult all pairs of particles,therefore it goes like N 2 .Instead of calculating:d 2r x xij i j 1 V r r f f r r2n2( n1)( ) i ( )i25Force calculationIf potential is not a very simple one thanuse look-up tables.For example for the Lenard – Jones potentialintroduce a cut-off at r c = 2.5σ.Then divide interval in K pieces with points:lk2(0, )kKr cr2cThen look-up table becomes:F( k) f lk26