Hi,

I am trying to solve numerically 13 differential equations with initial

boundary conditions in Mathematica. In my case, the boundary conditions

are not free parameters and those are constrained from experimental

observations.

But these set of equations and boundary condition give the error in NDSolve as following,

"NDSolve::ndsz: At e == 11.706899882374666`, step size is effectively zero; singularity or stiff system suspected. >>"

Because of this error, the plots of those 13 variables changes abruptly at "e == 11.706899882374666`".

I am getting nice curve upto this particular vaue of "e".

My question is , How can get a nice curve even after this value without changing the boundary conditions?

Thanks in advance.