Subject: G94: G94/DFT/Tr.State Problem

From: ipcakc@Postoffice (Dr.A.K.Chandra)
Date: Mon, 22 Jul 1996 19:54:20 -0500

Dear Netters,
I found some funny problem using B3LYP/6-31G** keyword for the following
transition state. It is a H-transfer process between two Cl atoms forming
a symmetric transition state

		Cl---------H---------Cl

with equal bond lengths. The Geometry optimisation leads to a perfectly
symmetric structure (B3lyp/6-31G**/UHF). The system is a doublet and is
a radical-molecule reaction.  Now, the fun is that the eigenvalue corresponding
to the imaginary frequency at the saddle point is ONLY ONE. But, if the
frequencies are seen, there are 3 IMAGINARY FREQUENCIES. The Keyword I have
used for optimisation of transition state is OPT=(TS,EF,CALCALL), hence
frequency calculation is done along with the optimisation.  The output is 
attached below.  

Can anyone help me in interpreting this result? 

Sincerely,
V. Sreedhara Rao.

		--------------------------------------------
			       V. Sreedhara Rao
			       Department of IPC,
			  Indian Institute of Science,
			   BANGALORE - 560 012. INDIA.

		   E-mail : [email-masked]
		--------------------------------------------

------------------------The output follows ----------------------
 **********************************************
 Gaussian 94:  IBM-RS6000-G94RevC.2  5-Aug-1995
                  12-Jul-1996
 **********************************************
 -----------------------------------------------------------
 #uhf 6-31g** opt=(ef,ts,calcall) b3lyp pop=full den=current
 -----------------------------------------------------------
 EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-
 ------------------------------------------------------------------------
                         Z-MATRIX (ANGSTROMS AND DEGREES)
 CD Cent Atom  N1     Length/X     N2    Alpha/Y     N3     Beta/Z      J
 ------------------------------------------------------------------------
   1   1  Cl
   2   2  H     1   1.497666(  1)
   3      X     2   1.000000(  2)   1   90.000(  4)
   4   3  Cl    2   1.497673(  3)   3   90.000(  5)   1  180.000(  6)   0
 ------------------------------------------------------------------------
 SCF Done:  E(UB+HF-LYP) =  -920.925868655     A.U. after   13 cycles
             Convg  =     .7439D-08             -V/T =  2.0030
             S**2   =    .7571
 Annihilation of the first spin contaminant:
 S**2 before annihilation      .7571,   after      .7500
 EIGENVECTOR FOLLOWING TRANSITION STATE SEARCH
 ANALYTICAL SECOND DERIVATIVES USED
 ITERATION   3
 EIGENVECTORS AND EIGENVALUES
                           1         2
     EIGENVALUES --     -.02252    .16489
       1  R1            -.70710    .70711
       2  R2             .70711    .70710
 TS SEARCH. TAKING P-RFO STEP
 SEARCHING FOR LAMDA THAT MAXIMIZES ALONG THE LOWEST MODE
 VALUE TAKEN    LAMDA=    .00000000
 SEARCHING FOR LAMDA THAT MINIMIZES ALONG ALL OTHER MODES
 VALUE TAKEN    LAMDA=    .00000000
 STEP TAKEN. STEPSIZE IS   .000014
 CURRENT PARAMETER VALUES (INTERNAL COORDINATES)
    I        X         GRADIENT    DISPLACEMENT       NEWX
    1    2.830179      -.000001       .000014      2.830193
    2    2.830192      -.000001       .000001      2.830193
         ITEM               VALUE     THRESHOLD  CONVERGED?
 MAXIMUM FORCE             .000001      .000450     YES
 RMS     FORCE             .000001      .000300     YES
 MAXIMUM DISPLACEMENT      .000014      .001800     YES
 RMS     DISPLACEMENT      .000010      .001200     YES

 *************************************************
 **  CONVERGENCE CRITERIA APPARENTLY SATISFIED  **
 *************************************************

                       ----------------------------
                       !   Optimized Parameters   !
                       ! (Angstroms and Degrees)  !
 ----------------------                            ----------------------
 !      Name          Value   Derivative information (Atomic Units)     !
 ------------------------------------------------------------------------
 !       R1          1.4977   -DE/DX =    0.                            !
 !       R2          1.4977   -DE/DX =    0.                            !
 ------------------------------------------------------------------------
 PREDICTED CHANGE IN ENERGY    .000000

 EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-EF-
 ------------------------------------------------------------------------
                         Z-MATRIX (ANGSTROMS AND DEGREES)
 CD Cent Atom  N1     Length/X     N2    Alpha/Y     N3     Beta/Z      J
 ------------------------------------------------------------------------
   1   1  Cl
   2   2  H     1   1.497666(  1)
   3      X     2   1.000000(  2)   1   90.000(  4)
   4   3  Cl    2   1.497673(  3)   3   90.000(  5)   1  180.000(  6)   0
 ------------------------------------------------------------------------
  Exact polarizability:  14.928    .000  14.928    .000    .000  53.183
 Approx polarizability:  15.126    .000  15.126    .000    .000  79.255
 Rotating electric field derivatives to standard orientation.
 Rotating nuclear coordinate derivatives to standard orientation.
 Full mass-weighted force constant matrix:
 Low frequencies ----1517.7789-1517.7789-1094.5308    -.0078    -.0064    -.0064
 Low frequencies ---    7.4380    7.4380  352.9932
 ******    3 imaginary frequencies (negative signs) ****** 
 Harmonic frequencies (cm**-1), IR intensities (KM/Mole),
 Raman scattering activities (A**4/AMU), Raman depolarization ratios,
 reduced masses (AMU), force constants (mDyne/A) and normal coordinates:
                     1                      2                      3
                    PI                     PI                     SG
 Frequencies -- -1517.7789             -1517.7789             -1094.5308
 Red. masses --     1.0219                 1.0219                 1.0219
 Frc consts  --     1.3870                 1.3870                  .7213
 IR Inten    --   460.3973               460.3973               446.2129
 Raman Activ --      .0000                  .0000                  .0000
 Depolar     --      .0000                  .0000                  .0000
 Atom AN      X      Y      Z        X      Y      Z        X      Y      Z
   1  17     -.01    .00    .00      .00   -.01    .00      .00    .00   -.01
   2   1     1.00    .00    .00      .00   1.00    .00      .00    .00   1.00
   3  17     -.01    .00    .00      .00   -.01    .00      .00    .00   -.01
                     4
                    SG
 Frequencies --   352.9932
 Red. masses --    34.9689
 Frc consts  --     2.5672
 IR Inten    --      .0000
 Raman Activ --      .0000
 Depolar     --      .0000
 Atom AN      X      Y      Z
   1  17      .00    .00    .71
   2   1      .00    .00    .00
   3  17      .00    .00   -.71

 -------------------
 - Thermochemistry -
 -------------------
 Temperature   298.150 Kelvin.  Pressure   1.00000 Atm.
 Atom  1 has atomic number 17 and mass  34.96885
 Atom  2 has atomic number  1 and mass   1.00783
 Atom  3 has atomic number 17 and mass  34.96885
 Molecular mass:    70.94553 amu.
 Principle axes and moments of inertia in atomic units:
                           1         2         3
     EIGENVALUES --      .00000 560.19741 560.19741
           X             .00000    .00000   1.00000
           Y             .00000   1.00000    .00000
           Z            1.00000    .00000    .00000
 THIS MOLECULE IS A PROLATE SYMMETRIC TOP.
 ROTATIONAL SYMMETRY NUMBER  1.
 WARNING-- ASSUMPTION OF CLASSICAL BEHAVIOR FOR ROTATION
           MAY CAUSE SIGNIFICANT ERROR
 ROTATIONAL TEMPERATURE (KELVIN)       .15461
 ROTATIONAL CONSTANT (GHZ)            3.221616
    3 IMAGINARY FREQUENCIES IGNORED.
 Zero-point vibrational energy       2111.4 (Joules/Mol)
                                     .50463 (Kcal/Mol)
 WARNING-- EXPLICIT CONSIDERATION OF   1 DEGREES OF FREEDOM AS
           VIBRATIONS MAY CAUSE SIGNIFICANT ERROR
 VIBRATIONAL TEMPERATURES:    507.88
          (KELVIN)
 
 Zero-point correction=                            .000804 (Hartree/Particle)
 Thermal correction to Energy=                     .003523
 Thermal correction to Enthalpy=                   .004467
 Thermal correction to Gibbs Free Energy=         -.023207
 Sum of electronic and zero-point Energies=           -920.925064
 Sum of electronic and thermal Energies=              -920.922346
 Sum of electronic and thermal Enthalpies=            -920.921402
 Sum of electronic and thermal Free Energies=         -920.949076
 
                         E                  CV                 S
                      KCAL/MOL        CAL/MOL-KELVIN    CAL/MOL-KELVIN
 TOTAL                    2.210              6.537             58.245
 ELECTRONIC                .000               .000              1.377
 TRANSLATIONAL             .889              2.981             38.695
 ROTATIONAL                .592              1.987             17.019
 VIBRATIONAL               .729              1.569              1.153
 VIBRATION  1              .729              1.569              1.153
                       Q            LOG10(Q)             LN(Q)
 TOTAL BOT        .472556D+11         10.674453         24.377872
 TOTAL V=0        .110751D+12         11.044347         25.229583
 VIB (BOT)        .521657D+00          -.282615          -.650746
 VIB (BOT)  1     .521657D+00          -.282615          -.650746
 VIB (V=0)        .122258D+01           .087278           .200965
 VIB (V=0)  1     .122258D+01           .087278           .200965
 ELECTRONIC       .200000D+01           .301030           .693147
 TRANSLATIONAL    .234881D+08          7.370848         16.972005
 ROTATIONAL       .192837D+04          3.285191          7.564431

 Internal  Forces:  Max      .000001377 RMS      .000000714
 1\1\GINC-IBM580_7\Freq\UB3LYP\6-31G(d,p)\Cl2H1(2)\IPCVSR\12-Jul-1996\1
 \\#UHF 6-31G** OPT=(EF,TS,CALCALL) B3LYP POP=FULL DEN=CURRENT\\clhcl-1
 .6 ang.\\0,2\Cl\H,1,R1\X,2,1.,1,90.\Cl,2,R2,3,90.,1,180.,0\\R1=1.49766
 611\R2=1.49767315\\Version=IBM-RS6000-G94RevC.2\State=2-SG\HF=-920.925
 8687\S2=0.757\S2-1=0.\S2A=0.75\RMSD=7.439e-09\RMSF=5.912e-07\Dipole=0.
 ,0.,0.0000045\DipoleDeriv=-0.3424881,0.,0.,0.,-0.3424881,0.,0.,0.,0.33
 71667,0.684973,0.,0.,0.,0.684973,0.,0.,0.,-0.6743387,-0.3424849,0.,0.,
 0.,-0.3424849,0.,0.,0.,0.3371721\Polar=14.9278148,0.,14.9278148,0.,0.,
 53.1825654\PG=C*V [C*(Cl1H1Cl1)]\NImag=3\\-0.02161655,0.,-0.02161655,0
 .,0.,0.07118866,0.04330625,0.,0.,-0.08661238,0.,0.04330625,0.,0.,-0.08