Problem in visu of Fext due to chipy.TimeEvolution_UpdateStep()
When Fext is imposed through chipy.CSpxx_ApplyPressure(), chipy.TimeEvolution_UpdateStep() sets the Fext array to zero. The problem comes from the order of the calls, between chipy.TimeEvolution_UpdateStep() and chipy.WriteDisplayFiles(). If chipy.TimeEvolution_UpdateStep() is called before chipy.WriteDisplayFiles(), the display files show Fext=0 even if Fext are not zero in the calculation.