Author Topic: RungeKutta Error  (Read 641 times)


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I made a mistake (I don't know where) and all executions are returning this message:

RUNGEKUTTA order 8 Problem: Errorflag:         -51
 Time   1.5000000000000000E-003 Step   1.0000000000000000E-003 Energy                       NaN
 Difficulties in the inversion of the rhos.    Using simplified inversion for the rhos.
 Nocc(           1 )=0d0                       NaN
 Nocc(           2 )=0d0                       NaN
 Product of Rho*(Rho^(-1))                       NaN

Can someone help me?

Thank you
« Last Edit: December 05, 2014, 07:18:26 PM by andre_smaira »


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Hello Andr?,

The problem you quote is with the integrator Runge Kutta of order 8 that you chose for the solution of the orbitals equations of motion. The energy and occupations seem to be undefined (NaN). In the future, please also post the input file "MCTDHB.inp" to make the analysis easier.

I think you specified the wrong file to read from, right? Anyways, I think we resolved this problem by renaming your *orbs.dat and *coefs.dat files?

I will take your post as a request to revise the input handling, especially, I would like to deprecate the restart from ASCII files with GUESS='DATA' in the near future.

Could you specify, what fixed the issue?