[molpro-user] CASVB multiple states

Michael Nix M.G.Nix at leeds.ac.uk
Tue Jul 16 15:50:57 BST 2013


Dear Molpro users,

Does anyone know if it is possible to get several states from a fully variational VB wavefunction calculation.  I have tried with water as a test case:
-------------INPUT-----------

hf

{multi
wf,10,1,0
state,2
locorb
}

{multi
wf,10,1,0
state,2
vb
}
------------------------------

The calculation runs seemingly ok, but the energies of both the states from the VB calculation are identical (see output below)

--------OUPUT-------------

1PROGRAM * MULTI (Direct Multiconfiguration SCF)       Authors: P.J. Knowles, H.-J. Werner (1984)     S.T. Elbert (1988)


Number of closed-shell orbitals:  1 (  1 )
Number of active  orbitals:       6 (  6 )
Number of external orbitals:     34 ( 34 )

State symmetry 1

Number of electrons:     8    Spin symmetry=Singlet   Space symmetry=1
Number of states:        2
Number of CSFs:        105   (225 determinants, 225 intermediate states)
1PROGRAM * CASVB (Valence bond MCSCF)       Authors: T. Thorsteinsson, D.L. Cooper (1996-2006)

Number of active electrons :   8
           active orbitals  :   6
           Total spin       : 0.0
           State symmetry   :   1
CI vector dump at record                3500.2

Molecular orbitals read from record     2140.2  Type=MCSCF/LOCALIZED (state averaged)

EXTRA SYMMETRY OF MOS IN SYMMETRY 1:   1 1 1 1 2 1 1 1 1 2   1 1 1 1 2 2 1 1 1 1   1 2 1 2 1 1 2 1 2 1   2 1 1 1 1 1 2 2 1 1
                                        1

Wavefunction dump at record             2141.2

Convergence thresholds  0.10E-01 (gradient)  0.10E-05 (energy)  0.10E-02 (step length)

Weight factors for state symmetry  1:    0.50000   0.50000

Number of orbital rotations:     244     (   6 Core/Active   34 Core/Virtual   0 Active/Active  204 Active/Virtual)
Total number of variables:       694


ITER. MIC  NCI  NEG     ENERGY(VAR)     ENERGY(PROJ)   ENERGY CHANGE     GRAD(0)  GRAD(ORB)   GRAD(CI)     STEP       TIME

   1  140    0    0     -76.05206612     -76.07266226   -0.02059614    0.15314356 0.00193678 0.00000000  0.81D+00      0.26
   2   27    0    0     -76.08094348     -76.08230019   -0.00135672    0.04037377 0.00000422 0.00000000  0.13D+00      0.35
   3   27    0    0     -76.08258017     -76.08264194   -0.00006177    0.01194359 0.00000761 0.00000000  0.23D-01      0.42
   4   27    0    0     -76.08266110     -76.08266831   -0.00000722    0.00429805 0.00000304 0.00000000  0.76D-02      0.48
   5   27    0    0     -76.08267124     -76.08267245   -0.00000121    0.00167699 0.00000131 0.00000000  0.33D-02      0.53
   6   27    0    0     -76.08267295     -76.08267317   -0.00000021    0.00067493 0.00000054 0.00000000  0.14D-02      0.57
   7   28    0    0     -76.08267326     -76.08267329   -0.00000004    0.00027557 0.00000022 0.00000000  0.62D-03      0.60

** WVFN ****  CONVERGENCE REACHED, FINAL GRADIENT:  0.11D-03

CASVB -- summary of results :
-----------------------------

Spatial VB configurations
-------------------------
     Conf. =>   Orbitals
       1   =>    1  1  2  2  3  4  5  6

Number of VB configurations :     1
           VB structures     :     2
           VB determinants   :     6

== Starting optimization - step  1 ========

Energy-based optimization (Evb).

Optimization algorithm:            dFletch
Maximum number of iterations:           50
Spin basis:                         Kotani

===========================================

Generate Kotani spin functions.
Converged ... maximum update to coefficient:  0.258742D-07
Final Evb :  -76.0826733083
Number of iterations used:   1

CASVB -- summary of results :
-----------------------------

== Wavefunction summary - step  2 =========

Orbital coefficients :
----------------------
          1          2          3          4          5          6
   1 -0.0911820 -0.2531360 -0.2289313 -0.3797013  0.2303814 -0.3799745
   2  0.2444897  0.6787421 -0.4572484  0.6986149  0.8081230  0.3118124
   3 -0.2445503 -0.6789103  0.8085066 -0.3119850 -0.4566062 -0.6986260
   4 -0.9337670 -0.1135207 -0.2680998  0.2580340  0.2689622  0.2578063
   5 -0.0096241 -0.0267182 -0.1119590 -0.4466633  0.0206513  0.0659489
   6  0.0096069  0.0266703  0.0204725 -0.0658775 -0.1122727  0.4466551

Overlap between orbitals :
--------------------------
          1          2          3          4          5          6
   1  1.0000000  0.4615698 -0.0370216  0.0444443  0.0358089  0.0446562
   2  0.4615698  1.0000000 -0.7673342  0.7629901  0.7661051  0.7630138
   3 -0.0370216 -0.7673342  1.0000000 -0.5052765 -0.8681430 -0.6877886
   4  0.0444443  0.7629901 -0.5052765  1.0000000  0.6871184  0.5877157
   5  0.0358089  0.7661051 -0.8681430  0.6871184  1.0000000  0.5039956
   6  0.0446562  0.7630138 -0.6877886  0.5877157  0.5039956  1.0000000

Structure coefficients :
------------------------
-0.17019896  0.98540972

Saving VB wavefunction to record :  3208.2

Evb :        -76.0826733083

Chirgwin-Coulson weights of structures :
----------------------------------------
VB spin+space (norm   1.00000000) :
-0.04226258  1.04226258
VB spin only  (norm 118.92355302) :
  0.02896769  0.97103231

Total number of structure transformations :            2495
Total number of Hamiltonian applications :             1188
Total number of 2-electron density evaluations :         74
Total number of Hessian applications :                 1077
Total number of pure orbital Hessian applications :     455
Approximate memory usage (8-byte words) :             10094

CASVB completed on 16-Jul-13 at 15:39:35 after     0.370 CPU seconds



Results for state 1.1
=====================

!MCSCF STATE 1.1 Energy              -76.082673308319
Nuclear energy                         8.90325418
Kinetic energy                        75.93525551
One electron energy                 -122.39794837
Two electron energy                   37.41202088
Virial ratio                           2.00194136

!MCSCF STATE 1.1 Dipole moment         0.00000000     0.00000016     0.76955895
Dipole moment /Debye                   0.00000000     0.00000042     1.95589563

Results for state 2.1
=====================

!MCSCF STATE 2.1 Energy              -76.082673308319
Nuclear energy                         8.90325418
Kinetic energy                        75.93525551
One electron energy                 -122.39794837
Two electron energy                   37.41202088
Virial ratio                           2.00194136

!MCSCF STATE 2.1 Dipole moment         0.00000000     0.00000016     0.76955895
Dipole moment /Debye                   0.00000000     0.00000042     1.95589563

State-averaged charge density matrix saved on record  2141.2 (density set 1)

!MCSCF expec         <1.1|DMY|1.1>     0.000000164276 au =     0.000000417521 Debye
!MCSCF trans         <2.1|DMY|1.1>     0.000000172427 au =     0.000000438236 Debye
!MCSCF expec         <2.1|DMY|2.1>     0.000000164276 au =     0.000000417521 Debye

!MCSCF expec         <1.1|DMZ|1.1>     0.769558945693 au =     1.955895625196 Debye
!MCSCF trans         <2.1|DMZ|1.1>    -0.552675809450 au =    -1.404669783781 Debye
!MCSCF expec         <2.1|DMZ|2.1>     0.769558945693 au =     1.955895625196 Debye

--------------------
The energies of the states in the preceding MO based MULTI are different and correct.
Any ideas what i'm doing wrong here?

Thanks
Mike



Dr. Mike Nix
Lecturer in Physical Chemistry
University of Leeds
LS2 9JT

+44(0)113 343 5960
m.g.nix at leeds.ac.uk

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