Error related to specified geometry - Calculation failed to converge


Just Got Here
Hi,
I'm an experimentalist who just started learning how to use NWChem. I'm having a problem when doing a geometry optimization for a compound; any suggestions on what I can do? I've increased the number of iterations from default to 5000 and it still wouldn't converge. Following is the input file:

title "TCP"
charge 0

geometry units angstroms print xyz
  C       -3.28602        1.98875       -3.71007
C -2.21452 1.34327 -2.88280
H -2.91702 2.17184 -4.72387
H -3.59895 2.94125 -3.26958
H -4.17384 1.35006 -3.76577
C -1.29877 2.12505 -2.17102
C -0.28598 1.51932 -1.42497
C -0.17776 0.12973 -1.38375
C -1.05980 -0.65500 -2.11855
C -2.07594 -0.04947 -2.86373
H -1.36831 3.21014 -2.19138
H 0.41661 2.13658 -0.87118
H -0.98218 -1.73725 -2.14154
H -2.75982 -0.67693 -3.43149
O 0.83874 -0.36919 -0.62363
P 0.84869 -1.81619 0.09275
O 2.28191 -1.82589 0.83988
O -0.16083 -1.65749 1.34916
C -1.51555 -1.67647 1.19218
C 3.49182 -1.82680 0.20626
O 0.61858 -3.01099 -0.79121
C -2.23553 -0.56837 1.62865
C -3.62357 -0.54356 1.48607
C -4.29866 -1.63910 0.93325
C -2.17203 -2.77681 0.65039
C 4.60971 -1.69909 1.03064
C 5.89349 -1.68421 0.48150
C 6.07051 -1.78876 -0.90202
C 4.94443 -1.93663 -1.72044
C 3.65878 -1.95116 -1.17011
C 7.44863 -1.81040 -1.49355
H 7.44580 -1.39212 -2.50559
H 7.82144 -2.83834 -1.53630
H 8.13981 -1.20739 -0.89533
H -1.72052 0.28420 2.06197
H -4.17515 0.33654 1.80850
C -3.56101 -2.75221 0.50995
H -4.06464 -3.61044 0.07048
H -1.62009 -3.65762 0.33353
C -5.78596 -1.59684 0.74312
H -6.26224 -0.99170 1.52168
H -6.21654 -2.60183 0.80452
H -6.02558 -1.16813 -0.23482
H 2.81566 -2.07211 -1.84347
H 5.05983 -2.04468 -2.79706
H 4.48458 -1.61254 2.10692
H 6.75307 -1.59083 1.14119
end

basis "ao basis" spherical
* library "6-31+G*"
end

driver
maxiter 1000
end


charge 0
dft
xc b3lyp
mult 1
iterations 5000
end
task dft optimize


   Calculation failed to converge
------------------------------
Total DFT energy = -1466.441934147101
One electron energy = -6797.811151187518
Coulomb energy = 3047.484874753834
Exchange-Corr. energy = -176.703731882821
Nuclear repulsion energy = 2460.588074169403

Numeric. integr. density =      194.000816767641

    Total iterative time =   5583.8s



driver: task_gradient failed                   0
------------------------------------------------------------------------
------------------------------------------------------------------------
current input line :
73: task dft optimize
------------------------------------------------------------------------
------------------------------------------------------------------------
There is an error related to the specified geometry
------------------------------------------------------------------------
For more information see the NWChem manual at
http://nwchemgit.github.io/index.php/NWChem_Documentation

Forum Vet
Please add the line

set quickguess t

before the task line and the system will converge.

Here is the modified input file

start tcp

title "TCP"

charge 0

geometry units angstroms print xyz
   C       -3.28602        1.98875       -3.71007
   C       -2.21452        1.34327       -2.88280
   H       -2.91702        2.17184       -4.72387
   H       -3.59895        2.94125       -3.26958
   H       -4.17384        1.35006       -3.76577
   C       -1.29877        2.12505       -2.17102
   C       -0.28598        1.51932       -1.42497
   C       -0.17776        0.12973       -1.38375
   C       -1.05980       -0.65500       -2.11855
   C       -2.07594       -0.04947       -2.86373
   H       -1.36831        3.21014       -2.19138
   H        0.41661        2.13658       -0.87118
   H       -0.98218       -1.73725       -2.14154
   H       -2.75982       -0.67693       -3.43149
   O        0.83874       -0.36919       -0.62363
   P        0.84869       -1.81619        0.09275
   O        2.28191       -1.82589        0.83988
   O       -0.16083       -1.65749        1.34916
   C       -1.51555       -1.67647        1.19218
   C        3.49182       -1.82680        0.20626
   O        0.61858       -3.01099       -0.79121
   C       -2.23553       -0.56837        1.62865
   C       -3.62357       -0.54356        1.48607
   C       -4.29866       -1.63910        0.93325
   C       -2.17203       -2.77681        0.65039
   C        4.60971       -1.69909        1.03064
   C        5.89349       -1.68421        0.48150
   C        6.07051       -1.78876       -0.90202
   C        4.94443       -1.93663       -1.72044
   C        3.65878       -1.95116       -1.17011
   C        7.44863       -1.81040       -1.49355
   H        7.44580       -1.39212       -2.50559
   H        7.82144       -2.83834       -1.53630
   H        8.13981       -1.20739       -0.89533
   H       -1.72052        0.28420        2.06197
   H       -4.17515        0.33654        1.80850
   C       -3.56101       -2.75221        0.50995
   H       -4.06464       -3.61044        0.07048
   H       -1.62009       -3.65762        0.33353
   C       -5.78596       -1.59684        0.74312
   H       -6.26224       -0.99170        1.52168
   H       -6.21654       -2.60183        0.80452
   H       -6.02558       -1.16813       -0.23482
   H        2.81566       -2.07211       -1.84347
   H        5.05983       -2.04468       -2.79706
   H        4.48458       -1.61254        2.10692
   H        6.75307       -1.59083        1.14119
end

basis "ao basis" spherical
 * library "6-31+G*"
end

driver
  maxiter 1000
end


charge 0
dft
  xc b3lyp
  mult 1
  iterations 5000
end

set quickguess t

task dft optimize


Just Got Here
That helps! Thank you much!


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