# sigularity problem in “NDSolve” in mathematica

I am trying to solve numerically 13 differential equations with intial 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 nice curve even after this value with out changing the boundary conditions?

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Can you provide some code, equations which you are dealing with... –  mmal Sep 13 at 8:18
Yaa, sure ...I am very new to this forum. Hence pls let me know, how can I send my code? –  user9497 Sep 13 at 9:46
@user9497 You can edit (button under the question) your question and put it there. Put 4 spaces before each line to create a code block. –  Kuba Sep 13 at 13:17
While the actual system would be nice, I expect it actually is a stiff system. There is another very similar post with an accepted answer at ...NDSolve::ndsz problem.... It may not be a complete answer to this particular system, the actual code being paramount here. –  J. W. Perry Sep 13 at 17:36
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