GAUSSIAN: ERROR from Stable=(Opt, Symm)



Dear CCLers,
     I have got an error message from GAUSSIAN 98 A.7 when Stable=(Opt, Symm)
 is employed.  The hightlight of the error from the output could be found at
 the end of this email.  But the strange point is that if I use Stable=(Opt)
 only, there's no problem (this is also attached at the end).  So what's
 wrong with it?  What should I do to solve it?
     I am a new to computational chemisty, any kind of suggetions or ideas
 would be helpful!  Thank you very much in advance!!
 Wishes,
 Kiniu
 ----
 Kiniu WONG (Kin-Yiu)
 Graduate Student
 Department of Physics
 The Ohio State University
 Email:  kiniu "at@at" mps.ohio-state.edu  or  kyiwong "at@at" phy.cuhk.edu.hk
 error output:
  %rwf=/usr/tmp/temp
  %int=/usr/tmp/temp
  %d2e=/usr/tmp/temp
  %scr=/usr/tmp/temp
  %chk=/usr/tmp/temp
  %Mem=400MB
  ----------------------------------------------------------------------
  #P UHF/6-31G(d) SCF=(Tight, direct, MaxCycle=128) Stable=(Symm, Opt) M
  axDisk=3GB Guess=CheckPoint Geom=AllCheck
  ----------------------------------------------------------------------
 ........
 ........
 .......
  Leave Link  202 at Sat Jul 28 07:57:49 2001, MaxMem=   52428800 cpu:
 0.1
  (Enter /usr/local/g98/l301.exe)
  Standard basis: 6-31G(d) (6D, 7F)
  There are   550 symmetry adapted basis functions of A   symmetry.
  Crude estimate of integral set expansion from redundant integrals=1.000.
  Integral buffers will be    131072 words long.
  Raffenetti 2 integral format.
  Two-electron integral symmetry is turned on.
    550 basis functions     1048 primitive gaussians
    119 alpha electrons      119 beta electrons
        nuclear repulsion energy      3694.9943364774 Hartrees.
  Leave Link  301 at Sat Jul 28 07:57:51 2001, MaxMem=   52428800 cpu:
 0.2
  (Enter /usr/local/g98/l302.exe)
  One-electron integrals computed using PRISM.
  NBasis=   550 RedAO= T  NBF=   550
  NBsUse=   550 1.00D-04 NBFU=   550
  Leave Link  302 at Sat Jul 28 07:58:06 2001, MaxMem=   52428800 cpu:
 9.2
 .......
 .....
  <S**2> of initial guess= 0.0000
  Leave Link  401 at Sat Jul 28 08:01:04 2001, MaxMem=   52428800 cpu:
 165.2
  (Enter /usr/local/g98/l503.exe)
  NBASIS 550 EXCEEDS MDIM 256
  Error termination via Lnk1e in /usr/local/g98/l503.exe.
 No error:
  %rwf=/usr/tmp/temp
  %int=/usr/tmp/temp
  %d2e=/usr/tmp/temp
  %scr=/usr/tmp/temp
  %chk=/usr/tmp/temp
  %Mem=400MB
  ----------------------------------------------------------------------
  #P UHF/6-31G(d) SCF=(Tight, Direct, MaxCycle=128) MaxDisk=3GB Stable=O
  pt
  ----------------------------------------------------------------------
 .........
 .......
  <S**2> of initial guess= 0.0000
  Leave Link  401 at Fri Feb  2 01:20:54 2001, MaxMem=   52428800 cpu:
 99.3
  (Enter /usr/local/g98/l502.exe)
  IExCor=   0 DFT=F Ex=HF Corr=None ScaHFX= 1.0000
  ScaDFX=  0.0000  0.0000  0.0000  0.0000
  IRadAn=      0 IRanWt=     -1 IRanGd=            0 ICorTp=0
  Using DIIS extrapolation.
  UHF open shell SCF:
 ........
 ......