EIGRL doesn't work with single element

[victorkemp]

This solves OK with MGIV but has no eigenvalue solution with EIGRL. Having more elements also solves OK with EIGRL.

SOL 105
CEND
DISPLACEMENT = ALL
SPC = 1
SUBCASE 1
LOAD = 1
SUBCASE 2
METHOD = 1
BEGIN BULK
GRID*                  1               0              0.              0.*       
*                     0.               0
GRID*                  2               0             0.6              0.*       
*                     0.               0
$--1---><------2-------><------3-------><------4-------><------5-------><--6--->
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ Material $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
MAT1*                  1           2.+11                              0.*       
*                     0.              0.              0.
$--1---><------2-------><------3-------><------4-------><------5-------><--6--->
SPC*                   1               1               1              0.*       
*                                                                       
SPC*                   1               1               2              0.*       
*                                                                       
SPC*                   1               1               3              0.*       
*                                                                       
SPC*                   1               1               4              0.*       
*                                                                       
SPC*                   1               1               5              0.*       
*                                                                       
SPC*                   1               1               6              0.*       
*                                                                       
$--1---><------2-------><------3-------><------4-------><------5-------><--6--->
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ Default $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
PBAR*                  1               1          0.0002   6.66666667-09*       
*          1.66666667-09   4.57760417-09              0.
CBAR*                  1               1               1               2*       
*                     0.              1.              0.
$--1---><------2-------><------3-------><------4-------><------5-------><--6--->
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ force $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
FORCE*                 1               2               0              1.*       
*                 -1000.              0.              0.
$--1---><------2-------><------3-------><------4-------><------5-------><--6--->
EIGRL*                 1                                               1*       
*                      0                              1.            MASS
ENDDATA