Hi everyone,
I’m currently performing a geometry optimization followed by a frequency calculation using wB97X-D/6-31G(d,p) in Q-Chem, but I’m consistently ending up with ~10 imaginary frequencies and unable to reach a true minimum. I’ve attached my input file for reference. Can anyone help me to figure this out.
$molecule
0 1
H -3.20772000 -2.19011000 -0.62114000
C -3.71852000 -1.23626000 -0.59028000
C -2.96384000 -0.01933000 -0.54290000
C -3.72734000 1.19258000 -0.50981000
H -3.22358000 2.14963000 -0.46451000
C -5.10513000 1.17839000 -0.52507000
H -5.64633000 2.11925000 -0.49690000
C -5.81140000 -0.02863000 -0.57397000
H -6.89633000 -0.03218000 -0.58620000
C -5.09635000 -1.23106000 -0.60598000
H -5.63064000 -2.17548000 -0.64488000
C -1.54138000 -0.01452000 -0.52969000
C -0.77101000 1.20694000 -0.52617000
C 0.58744000 1.21211000 -0.49953000
C 1.36643000 -0.00415000 -0.46952000
C 0.59593000 -1.22578000 -0.49625000
C -0.76232000 -1.23053000 -0.52461000
C 2.78682000 0.00070000 -0.41290000
C 3.54168000 1.21863000 -0.38056000
C 4.91835000 1.21333000 -0.32412000
C 5.63261000 0.01022000 -0.29561000
C 4.92642000 -1.19768000 -0.32411000
C 3.54986000 -1.21215000 -0.38052000
H -1.28021000 2.16163000 -0.55582000
H 1.09003000 2.17070000 -0.50707000
H 1.10510000 -2.18090000 -0.49439000
H -1.26472000 -2.18915000 -0.53919000
H 3.03195000 2.17335000 -0.39975000
H 5.45255000 2.15832000 -0.30107000
H 6.71670000 0.01387000 -0.25138000
H 5.46695000 -2.13906000 -0.30105000
H 3.04643000 -2.17020000 -0.39970000
N 0.12888000 0.01470000 4.19635000
C 0.93719000 1.14388000 3.72780000
C 0.78546000 2.38717000 4.59497000
C 0.67848000 -1.26157000 3.73127000
C 1.87531000 -1.72787000 4.55061000
C -1.27390000 0.16707000 3.80029000
C -2.23267000 -0.62686000 4.67870000
H 0.70300000 1.38338000 2.67484000
H 1.98667000 0.83921000 3.74403000
H -0.24160000 2.76222000 4.60430000
H 1.42567000 3.19118000 4.22060000
H 1.07390000 2.16928000 5.62698000
H 0.94814000 -1.20664000 2.66139000
H -0.10704000 -2.01759000 3.80780000
H 2.70772000 -1.02043000 4.50417000
H 2.23985000 -2.68980000 4.17857000
H 1.59441000 -1.84860000 5.60044000
H -1.41462000 -0.10697000 2.73922000
H -1.53464000 1.22555000 3.87826000
H -2.05221000 -1.70358000 4.62063000
H -3.26629000 -0.44959000 4.36800000
H -2.12972000 -0.32365000 5.72420000
$end
$rem
JOB_TYPE Optimization
METHOD wB97X-D
BASIS 6-31G(d,p)
SCF_CONVERGENCE 8
SCF_MAX_CYCLES 200
GEOM_OPT_MAX_CYCLES 200
SYMMETRY FALSE
SYM_IGNORE TRUE
CIS_N_ROOTS 3
CIS_SINGLETS TRUE
CIS_TRIPLETS FALSE
RPA TRUE
CIS_STATE_DERIV 1
SOLVENT_METHOD PCM
XC_GRID 2
$end
$pcm
THEORY CPCM
HeavyPoints 590
method swig
radii bondi
solver inversion
$end
$solvent
DIELECTRIC 37.5
OPTICALDIELECTRIC 1.8068
$end
@@@
$molecule
read
$end
$rem
JOB_TYPE Frequency
METHOD wB97X-D
BASIS 6-31G(d,p)
VIBMAN_PRINT 4
SCF_CONVERGENCE 8
SCF_MAX_CYCLES 100
SYMMETRY FALSE
SYM_IGNORE TRUE
CIS_N_ROOTS 3
CIS_SINGLETS TRUE
CIS_TRIPLETS FALSE
RPA TRUE
CIS_STATE_DERIV 1
SOLVENT_METHOD PCM
XC_GRID 2
MEM_TOTAL 248000
MEM_STATIC 4000
$end
$pcm
THEORY CPCM
HeavyPoints 590
method swig
radii bondi
solver inversion
$end
$solvent
DIELECTRIC 37.5
OPTICALDIELECTRIC 1.8068
$end