[lammps-users] warning: shake determinant < 0.0 ?

If you have any insights, plz let me know.

While running simulations of fluids consist of polymer chains, I used “fix shake” to fix C-H bond lengths.

However, warning message appeared and simulation stopped abnormally.

Warning message is “shake determinant < 0.0”

Do any of you know why this kind of warning caused?

What do I need to rectify to solve this problem?