Q j := ∑ i X _ i ∂ q j r _ i {\displaystyle {{Q}_{j}}:=\sum \limits _{i}{{{\underline {X}}_{i}}{{\partial }_{{q}_{j}}}{{\underline {r}}_{i}}}} Falls Konservativ
X _ i = − ∇ _ r _ i V ( r _ ) {\displaystyle {{\underline {X}}_{i}}=-{{\underline {\nabla }}_{{\underline {r}}_{i}}}V\left({\underline {r}}\right)}