*HEADING
: EIGENVALUE ANALYSIS OF AN UNCONSTRAINED 1-ELEMENT MESH  [M3D9]
*PREPRINT,ECHO=YES,HISTORY=NO,MODEL=NO
*NODE
1, 0.,  0.
3, 7.,  0.
5, 3.5, 3.5
7, 0.,  7.
9, 7.,  7.
*NGEN
1,3
3,9,3
7,9
1,7,3
*ELEMENT,TYPE=M3D9, ELSET=EALL
1 ,1 ,3 ,9 ,7 ,2 ,6 ,8 ,4 ,5
*MEMBRANE SECTION,MATERIAL=A1, ELSET=EALL
.1,
*MATERIAL,NAME=A1
*ELASTIC
3.E6      , 0.3
*DENSITY
7.5E-4, 
*STEP
*FREQUENCY, eigensolver=lanczos
20, , ,-1.E7
*OUTPUT,HISTORY,FREQUENCY=1
*MODAL OUTPUT
*END STEP