Warning: invalid value encountered in double_scalars

[wring]

Hello,
   When I finish the scf prosess,I go on calculating the curve of I-V.But it gives this error:Warning: invalid value encountered in double_scalars.I make sure that the convergence is suit for my setup.
   Thank you for your replies!
                                 wring
                                 2.19

[Anders Blom]

This is a numpy error. It indicates that your data somehow contains incorrect values, for example you try to take the square root of negative numbers, or 1/a where a (which is an array) contains zeroes.

I think this might be caused by your calculations not converging properly, perhaps to a state with no electrons left in the central region. Do you have the output log of the calculation?