negative/complex epsilon

Dear MPB users and Steven,
   
  I just started to use MPB and wanted to simulate a 2D trigonal lattice consisting of cylindrical rods of negative dielectric constant embedded in solution. I read the user reference for negative epsilon. It mentioned that one can use (allow-negative-epsilon) before (run). I added that into my ctl file. When i plotted band structures, i found, however, the frequency for the first TE band is negative. What did i do wrong? The neg-eps.ctl file is attached.
   
  The second question is about using anistropic dielectric constant. I wanted to see the band structures of complex epslion material. I want to set off-diagonal epsilon a complex number. I have configured "--with-hermitian-eps". But i got error as shown in the output file (petra.out) attached here. Also attached is the comp-eps.ctl file.
   
  I look forward to hearing from you!
   
  Thank you,
   
  Xiaoyang

       
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CHECK failure on line 139 of maxwell_eps.c: singular 3x3 matrix

Some deprecated features have been used.  Set the environment
variable GUILE_WARN_DEPRECATED to "detailed" and rerun the
program to get more information.  Set it to "no" to suppress
this message.
init-params: initializing eigensolver data
Computing 8 bands with 1.000000e-07 tolerance.
Working in 2 dimensions.
Grid size is 32 x 32 x 1.
Solving for 8 bands at a time.
Creating Maxwell data...
Allocating fields...
Mesh size is 3.
Lattice vectors:
     (0.866025, 0.5, 0)
     (0.866025, -0.5, 0)
     (0, 0, 1)
Cell volume = 0.866025
Reciprocal lattice vectors (/ 2 pi):
     (0.57735, 1, -0)
     (0.57735, -1, 0)
     (-0, 0, 1)
Geometric objects:
     cylinder, center = (0,0,0)
          radius 0.4, height 1e+20, axis (0, 0, 1)
Geometric object tree has depth 1 and 1 object nodes (vs. 1 actual objects)
Initializing dielectric function...