*HEADING
 COMPLEX EIGENVALUE EXTRACTION, 1-ELEMENT MESH  [CPE4]
*PREPRINT,ECHO=YES,HISTORY=NO,MODEL=NO
*NODE,NSET=NALL
 1, 0.,0.
 2, 1.,0.
 3, 1.,1.
 4, 0.,1.
*ELEMENT,TYPE=CPE4, ELSET=EALL
 1, 1,2,3,4
*SOLID SECTION,MATERIAL=A1, ELSET=EALL
*MATERIAL,NAME=A1
*ELASTIC
 1.,.3
*DENSITY
 1.,
*BOUNDARY
 1, ENCASTRE 
 2, ENCASTRE 
*STEP
*FREQUENCY
 4,
*OUTPUT,FIELD
*NODE OUTPUT
 U,
*ELEMENT OUTPUT
 S,
*END STEP
*STEP
*COMPLEX FREQUENCY
*END STEP