Dear NWChem developers and users:
I have been using NWChem 6.6 to perform computations on organometallic compounds using B3LYP/Lanl2DZ/6-311+G* for a couple of months now but I keep running in geometry convergence issues, i.e. I end up with one or two imaginary frequencies. I know this topic has been discussed numerous times in this forum but all solutions that seemed to work for the other users did not work for me. First of all here is my input file
start ProductCompound+Pd_ActivNewTry
title "ProductCompound+Pd_Activ in 6-311+g* basis set"
scratch_dir ../../../../var/scratch/user
memory total 8000 mb
charge 1
geometry units angstroms print xyz autosym
C -0.84169 -4.67838 -0.78686
C -1.65397 -3.38660 -0.96403
H -1.71396 -3.11420 -2.02404
H -2.68067 -3.53152 -0.62818
C -0.81108 -5.06104 0.70418
H -1.82691 -5.25146 1.06680
H -0.24681 -5.98894 0.84871
C 0.59057 -4.45649 -1.29716
H 1.18915 -5.36596 -1.17793
H 0.58450 -4.22342 -2.36829
C -1.03586 -2.19919 -0.15858
C -0.16400 -3.91760 1.50747
H -0.13525 -4.18115 2.57003
C 1.23527 -3.30783 -0.50083
H 2.25590 -3.13864 -0.86420
C -1.00137 -2.63356 1.33562
C 0.40263 -1.99950 -0.73850
C 1.26997 -3.69073 0.99150
H -2.02947 -2.81257 1.66299
H 1.85682 -4.60796 1.10790
H 1.78896 -2.93546 1.59039
H 0.26814 -1.91138 -1.82192
H -0.62254 -1.83117 1.97726
H -1.32011 -5.47621 -1.36413
C -2.03374 -1.02677 -0.30303
N -1.65887 0.28979 -0.39970
O -3.23714 -1.27466 -0.35105
C -2.68492 1.24806 0.05181
Pd 0.18915 1.02023 -0.40189
C -0.19606 3.93530 0.45343
C -0.93663 5.05841 0.77117
N -0.77952 2.74485 0.21089
H -3.49750 1.29078 -0.68187
H -3.14971 0.89072 0.97802
C -2.32714 4.94388 0.83541
C -2.11951 2.61368 0.27843
C -2.92018 3.71491 0.58740
H -0.43566 5.99866 0.96547
H -2.93777 5.80587 1.07986
H -3.99642 3.59503 0.63422
H 0.88556 3.96331 0.39216
C 1.23672 -0.78444 -0.35938
C 1.99822 -0.17545 -1.42220
C 1.56525 -0.36838 0.96422
C 2.90352 0.83525 -1.21601
C 2.42046 0.72670 1.18037
C 3.09822 1.33314 0.10341
H 1.83795 -0.53558 -2.43275
H 1.14869 -0.86934 1.82439
H 3.44415 1.25444 -2.05408
H 2.63506 1.06956 2.18525
O 3.91464 2.33607 0.41531
C 4.68995 2.99342 -0.60493
H 5.37414 2.28919 -1.08103
H 4.03828 3.45909 -1.34701
H 5.25736 3.75752 -0.08147
end
basis
H library 6-311+G*
O library 6-311+G*
N library 6-311+G*
C library 6-311+G*
Pd library lanl2dz_ecp
end
ecp
Pd library lanl2dz_ecp
end
stepper
maxiter 100
end
scf
thresh 1.0 d-8
end
dft
xc b3lyp
grid fine
tolerances tight
convergence energy 1.0d-8
iterations 100
end
task dft optimize
task dft freq
This was my last attempt to reach convergence, without success. Before I also tried
1. the "default" driver module with settings tight
2. did computations with and without "autosym"
3. changing the structure randomly to approach the minimum from different directions
4. use the normal vectors of the imaginary frequencies to change the structure along these normal vectors
All attempts without success and I always end up with imaginary frequencies (about -60 cm^-1). Does someone has another idea what to try and could this also come from an incorrect compilation of the NWChem code and corresponding libraries?
Best regards,
StarkEffect
|