Subject: qcisd(t)--very strange

From: "Shobe, Dave" <[email-masked]>
Date: Tue, 12 Dec 2000 09:15:23 -0500

Is it possible for the triples correction in qcisd(t) to leave the qcisd(t)
energy almost half a hartree higher than the qcisd energy?  
QCISD=-295.0176742 QCISD(T)=-294.5551278
These almost have to be different electronic states--but how did this
happen?  The molecule is CuF at R=1.7898 and (important hint?) this appears
to be one of those species that is poorly described by a single determinant.

--David Shobe

+++++++
 Iteration Nr.  31
 **********************
 DE(CORR)= -0.54044290D+00        E(CORR)=    -0.29501767435D+03
 NORM(A)=   0.25251768D+01
 Iteration Nr.  32
 **********************
 DE(CORR)= -0.54044284D+00        E(CORR)=    -0.29501767429D+03
 NORM(A)=   0.25251730D+01
 Iteration Nr.  33
 **********************
 DE(CORR)= -0.54044277D+00        E(CORR)=    -0.29501767422D+03
 NORM(A)=   0.25251714D+01
 Dominant configurations:
 ***********************
 Spin Case        I    J    A    B          Value
    AA            7        15           -0.622234D+00
    AA            7        18           -0.380065D+00
    AA            7        23           -0.239877D+00
    AA           14        15           -0.110013D+01
    AA           14        18           -0.640809D+00
    AA           14        19            0.138683D+00
    AA           14        23           -0.369077D+00
 Largest amplitude= 1.10D+00
 Time for triples=      253.00 seconds.
 T4(QCISD)= -0.33564626D+00
 T5(QCISD)=  0.79819266D+00
 QCISD(T)= -0.29455512782D+03

 **********************************************************************

            Population analysis using the SCF density.

 **********************************************************************

 Orbital Symmetries:
       Occupied  (SG) (SG) (SG) (PI) (PI) (SG) (SG) (PI) (PI) (DLTA)
                 (DLTA) (PI) (PI) (SG)
       Virtual   (SG) (PI) (PI) (SG) (SG) (PI) (PI) (SG) (SG) (PI)
                 (PI) (SG) (PI) (PI) (DLTA) (DLTA) (SG) (PI) (PI)
                 (SG) (PI) (PI) (SG) (DLTA) (DLTA) (PI) (PI) (SG)
                 (PI) (PI) (SG) (SG) (SG) (PI) (PI) (DLTA) (DLTA)
                 (PHI) (PHI) (DLTA) (DLTA) (PI) (PI) (SG) (SG)
  The electronic state is 1-SG.
 Alpha  occ. eigenvalues --  -26.13096  -5.07945  -3.41969  -3.41949
-3.41949
 Alpha  occ. eigenvalues --   -1.39304  -0.56693  -0.55033  -0.55033
-0.52642
 Alpha  occ. eigenvalues --   -0.52642  -0.46388  -0.46388  -0.44056
 Alpha virt. eigenvalues --   -0.01912   0.03765   0.03765   0.04025
0.06136
 Alpha virt. eigenvalues --    0.11920   0.11920   0.16392   0.22087
0.30468
 Alpha virt. eigenvalues --    0.30468   0.38673   0.38858   0.38858
0.41456
 Alpha virt. eigenvalues --    0.41456   0.43247   0.52223   0.52223
0.57931
 Alpha virt. eigenvalues --    0.73282   0.73282   0.79438   1.42810
1.42810
 Alpha virt. eigenvalues --    1.43659   1.43659   1.53722   1.63362
1.63362
 Alpha virt. eigenvalues --    1.69512   2.57754   4.28567   4.34819
4.34819
 Alpha virt. eigenvalues --    4.37817   4.37817   4.39725   4.39725
4.40072
 Alpha virt. eigenvalues --    4.40072   4.48642   4.48642   4.77192
6.70815
          Condensed to atoms (all electrons):
              1          2
  1  Cu  18.151326   0.149695
  2  F    0.149695   9.549284
 Total atomic charges:
              1
  1  Cu   0.698979
  2  F   -0.698979
 Sum of Mulliken charges=   0.00000
 Atomic charges with hydrogens summed into heavy atoms:
              1
  1  Cu   0.698979
  2  F   -0.698979
 Sum of Mulliken charges=   0.00000
 Electronic spatial extent (au):  <R**2>=   110.3634
 Charge=     0.0000 electrons
 Dipole moment (Debye):
    X=     0.0000    Y=     0.0000    Z=     6.7118  Tot=     6.7118
 Quadrupole moment (Debye-Ang):
   XX=   -15.4538   YY=   -15.4538   ZZ=   -20.4852
   XY=     0.0000   XZ=     0.0000   YZ=     0.0000
 Octapole moment (Debye-Ang**2):
  XXX=     0.0000  YYY=     0.0000  ZZZ=    22.4589  XYY=     0.0000
  XXY=     0.0000  XXZ=     4.5154  XZZ=     0.0000  YZZ=     0.0000
  YYZ=     4.5154  XYZ=     0.0000
 Hexadecapole moment (Debye-Ang**3):
 XXXX=   -11.1625 YYYY=   -11.1625 ZZZZ=   -94.9676 XXXY=     0.0000
 XXXZ=     0.0000 YYYX=     0.0000 YYYZ=     0.0000 ZZZX=     0.0000
 ZZZY=     0.0000 XXYY=    -3.7208 XXZZ=   -16.1866 YYZZ=   -16.1866
 XXYZ=     0.0000 YYXZ=     0.0000 ZZXY=     0.0000
 N-N= 5.055833589172D+01 E-N=-8.251139679182D+02  KE= 2.289446475560D+02
 Symmetry A1   KE= 1.404033163033D+02
 Symmetry A2   KE= 1.875292004753D+01
 Symmetry B1   KE= 3.489420560260D+01
 Symmetry B2   KE= 3.489420560260D+01
 1|1|UNPC-UNK|SP|RQCISD(T)-FC|Gen|Cu1F1|PCUSER|11-Dec-2000|0||#N QCISD(
 T) LANL2DZ EXTRABASIS||copper fluoride qcisd(t)//b3lyp/LANL2DZ++**||0,
 1|Cu|F,1,1.7898||Version=x86-Win32-G98RevA.9|State=1-SG|HF=-294.477231
 5|MP2=-295.0021973|MP3=-294.9326273|MP4D=-294.9593718|MP4DQ=-294.96448
 97|MP4SDQ=-294.9982426|QCISD=-295.0176742|QCISD(T)=-294.5551278|RMSD=7
 .342e-009|PG=C*V [C*(F1Cu1)]||@

 MARY HAD A LITTLE LAMB
      HIS FEET WERE BLACK AS SOOT,
           AND EVERYWHERE THAT MARY WENT
                HIS SOOTY FOOT HE PUT.

                    -- NONAME
 Job cpu time:  0 days  0 hours 25 minutes 46.0 seconds.
 File lengths (MBytes):  RWF=  116 Int=    0 D2E=    0 Chk=   11 Scr=    1
 Normal termination of Gaussian 98.