[CPMD-list] negative frequencies obtained after vibrational analysis

[Nagesh Babu Idupulapati]

Dear all

I did geometry optimization for a particular system and then  
vibrational analysis to find out whether the optimized system is  
ground state or not.

 From the output file, I found more negative harmonic frequencies as  
shown below:


OUTPUT FILE FROM VIBRATIONAL ANALYSIS:

HARMONIC FREQUENCIES [cm**-1]:

      -72559.0607     -28053.3624      -1009.0848           .0012
            .0046           .0081           .0101           .0115
            .0157         18.6252         39.0220         73.4002
         116.7141        154.5234        173.8586        201.6628
         220.9176        256.0662        296.8070        332.7523
         363.5320        399.6134        431.5199        440.6355
         470.9136        574.6108        616.0671        706.9157
         747.3491        755.0097        911.3156        919.7400
         958.6060        989.3233       1006.1774       1106.1862
        1131.0953       1231.7557       1332.8774       1413.1510
        1498.2678       1533.5184       1557.4826       1631.7889
        1686.4245       1703.0891       1745.2832       1789.1454
        1797.5490       1843.1250       1846.2055       1874.8920
        1906.9333       1917.7131       1941.1129       1980.2365
        2004.9025       2041.1756       2053.9534       2094.8480
        2106.4196       2154.1094       2168.2487       2188.9673
        2234.3142       2254.7786       2268.4013        
2272.4823................
................................................................................

So my question is, the geometry optimization parameters I used in my  
input file were not sufficient to obtain the ground state?


INPUT FILE:

  &CPMD
   GEOMETRY OPTIMIZATION XYZ
   CONVERGENCE INITIAL
    1.0d-5
   CONVERGENCE GEOMETRY
    1.0d-6
   CONVERGENCE ORBITALS
    1.0d-7
   CONVERGENCE ADAPT
    0.02
   CONVERGENCE ENERGY
    0.05
  RESTART WAVEFUNCTION COORDINATES LATEST

SPLINE POINTS
    3000

   CENTER MOLECULE ON
   STRUCTURE BONDS
   STRUCTURE ANGLES
  &END

  &SYSTEM
    ANGSTROM
    SYMMETRY
    0
    CELL ABSOLUTE
    29.0  29.0  17.5  0  0  0
    CUTOFF
    80.0
    CHARGE
    1
  &END

  &ATOMS
*C_MT_GIA_BLYP   KLEINMAN-BYLANDER
    LMAX=P
    19

*O_MT_GIA_BLYP  KLEINMAN-BYLANDER
    LMAX=P
    13

*N_MT_GIA_BLYP KLEINMAN-BYLANDER
    LMAX=P
    3

*Ca_SEMI_BLYP_GIA.psp KLEINMAN-BYLANDER
   LMAX=D LOC=S
   1

*H_GIA_BLYP KLEINMAN-BYLANDER
   LMAX=S
   16


&END

  &DFT
    NEWCODE
    FUNCTIONAL BLYP
  &END
...............................................................................

Can somebody Please let me know how to obtain all positive frequencies  
for this system?

Regards

Nagesh.



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