problem with eigen values

[samcivil]

Dear silvia
Hollo
when i run eigen values,I get this error
please help me
eigen 1
BandArpackSolver::Error in dgbtrf_
Warning FrequencyAlgo::solveCurrentStep<> - the EigenSOE failed in solve<>.
EigenAnalysis::analyze<> - algoritm failed

[canim_ken]

First, you must know that, eigen command calculates N-1 number of eigen valuse which N is Number of DOFs of the structure which have masses.
Second, Are you sure your structure has not any stability problems?

[samcivil]

Hello,
I don't have problem with sac3,my problem is in sac9 ,sac20 buildings.and I think it is because of numbea of stories.and problem ios in mass definition.
Thank you,but if you have any other idea,please ha\elp me.

[canim_ken]

Do you have a 3D model? If you have your model in SAP2000, I have developed a software which can easily export your model from SAP2000 to OpenSEES. for both 3D and 2D Steel Moment Resisting Frames. So I think I can convert your SAP2000 model to OpenSEES.