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