Quote:Edoapra Jan 16th 11:12 pmSophia
If you look at the frequencies output, you will find the section " Negative Nuclear Hessian Mode 1 "
If you use as new geometry the one as listed under
" Geometry after -100.0% step for mode 1;" ...
Then, if you re-run the calculation with this new geometry, all frequencies will be positive
I have a similar problem with a negative-frequency mode (even the frequency value is similar -167.765 [cm**-1]) despite the tighter energy convergence and optimisation used. I have tried to follow this advice to put new geometry from " Geometry after -100.0% step for mode 1;" in the input file and re-run the calculation but it did not help. It converged to a bit lower energy but the mode is still at the negative frequency.
My input file:
start PCO
echo
scratch_dir .
permanent_dir .
memory 6000 mb
charge -5
geometry units angstroms
O 2.63694460 3.94597618 -0.00000016
C 2.90591488 2.64073309 -0.00000013
O 1.89749032 1.74606799 -0.00000006
O 4.16999971 2.21992605 -0.00000016
O -0.01986707 0.00426229 1.90601275
Pu -0.02688600 -0.00141010 0.00000009
O -0.01986716 0.00426243 -1.90601265
O -4.00241237 2.53107489 -0.00000018
O 0.53932580 -2.50059322 -0.00000008
C -3.73858336 1.22669983 -0.00000014
C 0.81223868 -3.82105873 -0.00000012
O -4.73281162 0.34093790 -0.00000017
O -2.45996385 0.79869299 -0.00000004
O -0.18408865 -4.70381661 -0.00000013
O 2.07680464 -4.23684930 -0.00000013
end
BASIS
Pu library "Stuttgart_RLC_ECP"
C library "Stuttgart_RLC_ECP"
O library "Stuttgart_RLC_ECP"
END
ECP
Pu library "Stuttgart_RLC_ECP"
C library "Stuttgart_RLC_ECP"
O library "Stuttgart_RLC_ECP"
END
dft
xc b3lyp
noio
direct
vectors input PCO_01.movecs output PCO.movecs
iterations 5000
convergence energy 5d-9 damp 40 ncydp 0 dampon 1d99 dampoff 1d-4 rabuck 20 levlon 0.2
smear
grid fine
odft
mult 4
end
driver
tight
MAXITER 600
end
set int:txs:limxmem 25621940
set driver:linopt 0
task dft optimize
task dft freq
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