potential energy scan over a bond fails


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Hi,

I am testing to get relation between bond length(Rcn) and potential energy(Vcn) of ACN by changing C-N bond length. The equilibrium bond length is 1.16981 A and I reduce it by 0.02 angstrom per step with geometry adjust as shown below.
Rcn Energy Energy diff(Hartree)
1.14981 -132.410048135618 0.000893164381978
1.16981 -132.4109413 0

But when i change bond length to 1.12981 A(3.4% decrease from equilibrium) and 1.10981 (5.1% decrease from equilibrium) and encountered error when running nwchem with following input. What might be the reasons and solutions for these errors? Thanks


Input for Rcn= 1.12981

Title "CN_SCAN"

Start CN_SCAN

echo

charge 0

geometry noautosym units angstrom
N      0.00000000     0.00000000     1.45215878
C 0.00000000 -0.00000000 0.28234682
C 0.00000000 -0.00000000 -1.19525538
H 0.73202481 0.73202481 -1.56652446
H 0.26793968 -0.99996449 -1.56652446
H -0.99996449 0.26793968 -1.56652446
end

geometry adjust
   zcoord
bond 1 2 cccc 1.129810 constant
end
end

ecce_print ecce.out

 
basis spherical noprint
  * library aug-cc-pVDZ 
end
 
scf
  thresh 1.0e-10 
tol2e 1.0e-10
singlet
rhf
maxiter 100
end

ccsd
 thresh 1e-07
maxiter 999
freeze core 0
end

driver
 tight
maxiter 100
end

task ccsd energy

Output Section:

                              Z-matrix (autoz)
--------

Units are Angstrom for bonds and degrees for angles

     Type          Name      I     J     K     L     M      Value
----------- -------- ----- ----- ----- ----- ----- ----------
1 Stretch 1 2 1.16981
2 Stretch 2 3 1.47760
3 Stretch 3 4 1.09980
4 Stretch 3 5 1.09980
5 Stretch 3 6 1.09980
6 Bend 1 3 4 109.72941
7 Bend 1 3 5 109.72941
8 Bend 1 3 6 109.72941
9 Bend 2 3 4 109.72941
10 Bend 2 3 5 109.72941
11 Bend 2 3 6 109.72941
12 Bend 4 3 5 109.21180
13 Bend 4 3 6 109.21180
14 Bend 5 3 6 109.21180
15 Torsion 1 2 4 3 -180.00000
16 Torsion 1 2 5 3 180.00000
17 Torsion 1 2 6 3 -180.00000


 Constants are marked with an asterisk (*).

     Type          Name      I     J     K     L     M      Value
----------- -------- ----- ----- ----- ----- ----- ----------
1*Stretch cccc 1 2 1.12981
2 Stretch 2 3 1.47760
3 Stretch 3 4 1.09980
4 Stretch 3 5 1.09980
5 Stretch 3 6 1.09980
6 Bend 1 3 4 109.72941
7 Bend 1 3 5 109.72941
8 Bend 1 3 6 109.72941
9 Bend 2 3 4 109.72941
10 Bend 2 3 5 109.72941
11 Bend 2 3 6 109.72941
12 Bend 4 3 5 109.21180
13 Bend 4 3 6 109.21180
14 Bend 5 3 6 109.21180
15 Torsion 1 2 4 3 180.00000
16 Torsion 1 2 5 3 180.00000
17 Torsion 1 2 6 3 -180.00000

      Multipole analysis of the density wrt the origin
------------------------------------------------


    L   x y z        total         open         nuclear
- - - - ----- ---- -------
0 0 0 0 -0.000000 0.000000 22.000000

    1   1 0 0      0.000000      0.000000      0.000000
1 0 1 0 0.000000 0.000000 0.000000
1 0 0 1 -1.659949 0.000000 -0.251976

    2   2 0 0    -13.219779      0.000000      5.740775
2 1 1 0 -0.000000 0.000000 -0.000000
2 1 0 1 -0.000000 0.000000 0.000000
2 0 2 0 -13.219779 0.000000 5.740775
2 0 1 1 -0.000000 0.000000 0.000000
2 0 0 2 -15.718319 0.000000 108.447403


Parallel integral file used     208 records with       0 large values



                  Four-Index Transformation
-------------------------
Number of basis functions: 96
Number of shells: 42
Number of occupied orbitals: 11
Number of occ. correlated orbitals: 11
Block length: 16
Superscript MO index range: 1 - 11
Subscript MO index range: 1 - 96
MO coefficients read from: ./CN_SCAN.movecs
Number of operator matrices in core: 132
Half-transformed integrals produced

    Pass:    1     Index range:    1  -   11     Time:      2.81
------------------------------------------
MP2 Energy (coupled cluster initial guess)
------------------------------------------
Reference energy: -131.943768376969416
MP2 Corr. energy: -0.441754295802068
Total MP2 energy: -132.385522672771486




****************************************************************************
the segmented parallel ccsd program: 16 nodes
****************************************************************************




level of theory    ccsd
number of core 0
number of occupied 11
number of virtual 85
number of deleted 0
total functions 96
number of shells 42
basis label 566



  ***** ccsd parameters *****
iprt = 0
convi = 0.100E-06
maxit = 999
mxvec = 5
memory 26201787
Restarting from old vector in ./CN_SCAN.t2




iter     correlation     delta       rms       T2     Non-T2      Main
energy energy error ampl ampl Block
time time time


  1     -0.4646524964 -4.647D-01  8.804D-02    26.16     0.00    25.31
2 -0.4615787896 3.074D-03 1.348D-02 5.33 0.00 4.53
3 -0.4633856973 -1.807D-03 5.469D-03 5.54 0.00 4.76
4 -0.4632846228 1.011D-04 3.195D-03 5.93 0.02 4.53
5 -0.4680386121 -4.754D-03 1.385D+00 10.08 0.00 9.16
6 -1.2258434762 -7.578D-01 1.646D+04 1.01 0.00 0.03
7 31027.1766174762 3.103D+04 4.786D+05 0.91 0.00 0.02
8****************** 8.402D+08 1.640D+07 0.90 0.00 0.02
9****************** 2.334D+13 4.079D+10 0.81 0.00 0.02

Compare input showing that only bond length changes,

[nshen@login2 13]$ diff *.nw ../14/*.nw
21c21
< bond 1 2 cccc 1.109810 constant
---
> bond 1 2 cccc 1.129810 constant


Output Section with another bond length

 Constants are marked with an asterisk (*).

     Type          Name      I     J     K     L     M      Value
----------- -------- ----- ----- ----- ----- ----- ----------
1*Stretch cccc 1 2 1.10981

...

      Multipole analysis of the density wrt the origin
------------------------------------------------

    L   x y z        total         open         nuclear
- - - - ----- ---- -------
0 0 0 0 -0.000000 0.000000 22.000000

    1   1 0 0      0.000000      0.000000      0.000000
1 0 1 0 0.000000 0.000000 -0.000000
1 0 0 1 -1.641985 0.000000 -0.377958

    2   2 0 0    -13.155013      0.000000      5.740775
2 1 1 0 -0.000000 0.000000 -0.000000
2 1 0 1 -0.000000 0.000000 0.000000
2 0 2 0 -13.155013 0.000000 5.740775
2 0 1 1 -0.000000 0.000000 -0.000000
2 0 0 2 -15.697384 0.000000 107.032547

------------------------------------------------------------------------
multipole: rtdb? 0
------------------------------------------------------------------------
An error occured in the Runtime Database
------------------------------------------------------------------------
For more information see the NWChem manual at http://nwchemgit.github.io/index.php/NWChem_Documentation


For further details see manual section:                                                                                                       


multipole: rtdb? 0

I am not sure what causes the error in the runtime database

Forum Vet
Freephys,
I have not been able to reproduce your failure with NWChem 6.3 (in other words, my job completed with no failures).
Could you provide more details about your runs (e.g. NWChem version, hardware, etc ...)?

I would try to restart your calculations after the deleting the CN_SCAN.t2 amplitudes file.

By the way, you might want to modify your freeze line in the ccsd input block,
the aug-ccpvdz basis set is meant to be used to correlate just the valence electrons.
The freeze line should be changed to


freeze atomic


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