UT theoretical chemistry code forum

hi, everyone

I do a dimer calculation for ethylene epoxidation, but find the convergence of dimer calculation is
very slow. I check the DIMCAR file as :
3 0.07815 3.13550 -185.42058 -5.30793 3.12832
3 0.07815 1.80638 -185.42058 -5.14717 1.45439
3 0.07815 2.13081 -185.42058 -5.15869 1.66550
3 0.07815 1.01386 -185.42058 -5.17759 2.16418
4 0.07150 1.08845 -185.42068 -5.41249 1.38171
4 0.07150 0.72022 -185.42068 -5.37324 0.64937
5 0.08961 1.22189 -185.42090 -5.65767 2.28732
5 0.08961 1.03885 -185.42090 -5.59987 1.40262
5 0.08961 0.55215 -185.42090 -5.61837 0.50121
6 0.09451 4.38350 -185.42100 -4.92702 4.76668
6 0.09451 3.76876 -185.42100 -5.21543 3.97478
6 0.09451 0.97105 -185.42100 -5.42790 1.20180
7 0.08799 3.19770 -185.42113 -4.97134 3.73344
7 0.08799 2.37494 -185.42113 -5.11100 1.87169
7 0.08799 1.86379 -185.42113 -5.14644 2.29941
7 0.08799 0.63956 -185.42113 -5.20526 0.90693
8 0.08724 1.40165 -185.42134 -4.99486 2.04857
8 0.08724 1.65342 -185.42134 -4.79008 2.12877
8 0.08724 0.82932 -185.42134 -4.80999 1.12542
9 0.08715 2.67310 -185.42140 -5.15454 4.45103
9 0.08715 4.24303 -185.42140 -4.88759 5.29572
9 0.08715 4.10117 -185.42140 -4.87129 -7.21016
9 0.08715 2.19686 -185.42140 -5.12005 3.29717
10 0.10329 3.40101 -185.42152 -4.40950 -5.43741
10 0.10329 2.02895 -185.42152 -4.63915 0.20135
10 0.10329 2.01802 -185.42152 -4.62350 0.10768
10 0.10329 2.00978 -185.42152 -4.61755 0.20284
11 0.09032 5.10344 -185.42163 -4.43023 4.86921
11 0.09032 5.54985 -185.42163 -4.17877 5.55195
11 0.09032 1.62290 -185.42163 -4.70679 1.04816
11 0.09032 1.48650 -185.42163 -4.69402 1.02575
12 0.09467 1.68316 -185.42189 -5.02630 0.94141
12 0.09467 1.48618 -185.42189 -5.01144 1.59995
12 0.09467 5.63794 -185.42189 -4.78945 8.69025
12 0.09467 6.39239 -185.42189 -4.21406 -8.76764
13 0.07761 8.44327 -185.42203 -5.81341 9.56179
13 0.07761 8.18798 -185.42203 -3.59798 8.94721
13 0.07761 1.48118 -185.42203 -4.91209 1.27133
13 0.07761 1.77642 -185.42203 -4.93553 1.95644
14 0.06479 1.40968 -185.42220 -4.98999 1.84445
14 0.06479 1.41155 -185.42220 -5.08275 2.23656
14 0.06479 1.32943 -185.42220 -5.09757 1.27481
14 0.06479 0.72826 -185.42220 -5.10614 0.85535

my question is : Can I get a converged results in this calculation.
INCAR for this cal. is attached:
PREC=Normal
NPAR=16
ISTART = 0
ICHARG = 2
INIWAV=1
ISYM=0
ISPIN=1
LWAVE = .FALSE.
Electronic Relaxation:
LREAL=Auto
ENCUT= 400
# ENAUG=400
NELM=60
IALGO=48

DOS related values :
ISMEAR = 0
SIGMA = 0.05

SYSTEM = Typical Dimer Run
IBRION=3
POTIM=0.0
NSW=600
EDIFF=1E-7
EDIFFG=-0.005
LWAVE=.FALSE.
LCHARG=.FALSE.

# DIMER PARAMETERS
ICHAIN=2
DdR=0.005
DRotMax=4
DFNMin=0.01
DFNMax=1.0

# OPTIMIZER PARAMETERS
IOPT=1

the force is oscillated:
14 0.06479 1.40968 -185.42220 -4.98999 1.84445
14 0.06479 1.41155 -185.42220 -5.08275 2.23656
14 0.06479 1.32943 -185.42220 -5.09757 1.27481
14 0.06479 0.72826 -185.42220 -5.10614 0.85535
15 0.08206 1.61608 -185.42221 -5.38391 1.70230
15 0.08206 0.92245 -185.42221 -5.28162 1.58373
16 0.11200 1.17315 -185.42231 -4.91726 1.33278
16 0.11200 0.91026 -185.42231 -4.91574 2.20165
17 0.09798 1.14512 -185.42247 -5.11718 1.11645

How can improve my calculation?

Step Force Torque Energy Curvature Angle
1 0.09893 1.05350 -185.44409 -3.40655 1.34158
1 0.09893 0.94910 -185.44409 -3.41265 3.17259
2 0.08370 0.77284 -185.44444 -3.45949 2.53943
3 0.08638 0.83361 -185.44465 -3.43644 1.72888
4 0.06761 0.87287 -185.44465 -3.30945 1.70701
5 0.10317 1.14589 -185.44498 -3.00143 2.29727
5 0.10317 1.13724 -185.44498 -3.02235 2.19810
5 0.10317 0.96118 -185.44498 -2.99950 2.78590
6 0.05413 1.56401 -185.44505 -3.40178 2.14855
6 0.05413 1.38645 -185.44505 -3.58072 2.44851
6 0.05413 1.62488 -185.44505 -3.55903 1.32383
6 0.05413 0.68363 -185.44505 -3.56766 0.68928
7 0.05876 1.26386 -185.44511 -3.32407 1.45637
7 0.05876 1.93111 -185.44511 -3.35881 2.48184
7 0.05876 1.63596 -185.44511 -3.54488 1.73757
7 0.05876 1.13492 -185.44511 -3.24935 0.82940
7 0.05876 1.25439 -185.44511 -3.30913 0.92912
7 0.05876 0.57246 -185.44511 -3.39096 1.42691
8 0.06095 0.98061 -185.44520 -3.18879 1.22380
9 0.06772 1.11355 -185.44531 -3.05714 2.72586
9 0.06772 1.38429 -185.44531 -3.09718 1.20997
9 0.06772 0.58501 -185.44531 -3.13652 1.27603
10 0.06261 0.68107 -185.44531 -3.20658 2.06275
11 0.07542 0.86507 -185.44570 -2.66448 1.31714
12 0.09915 1.20721 -185.44584 -2.60350 3.67015
12 0.09915 1.94442 -185.44584 -2.77387 2.11328
12 0.09915 1.29174 -185.44584 -2.83728 1.54688
12 0.09915 1.78802 -185.44584 -2.78825 1.36523
12 0.09915 0.90536 -185.44584 -2.84620 0.43402
13 0.12537 1.48885 -185.44595 -3.15168 0.69621

I changed some parameters, e.g.
EDIFF=1E-7
DRotmax=10
IOPT=1.
But, I cann't get a convergence results still.
which parameter is determinant in my case?
I will be appreciated for your any suggestion.

Fortunately, I figured it out.
Step Force Torque Energy Curvature Angle
1 0.02841 3.18401 -185.44729 -2.46620 3.84377
1 0.02841 3.56424 -185.44729 -2.13899 3.61220
1 0.02841 1.43690 -185.44729 -2.35666 1.69127
1 0.02841 0.80553 -185.44729 -2.38181 1.69648
2 0.02900 0.95919 -185.44728 -2.49556 0.99450
3 0.02987 0.95197 -185.44728 -2.50336 2.00048
4 0.02374 1.24798 -185.44729 -2.58269 0.93418
4 0.02374 0.47801 -185.44729 -2.57408 1.49013
5 0.02369 0.96171 -185.44730 -2.57901 1.20593
6 0.02634 1.14183 -185.44732 -2.63253 2.50748
6 0.02634 1.32422 -185.44732 -2.67121 1.00139
6 0.02634 0.60571 -185.44732 -2.63181 1.84517
7 0.01818 0.79457 -185.44732 -2.67389 0.78731
8 0.03752 0.71775 -185.44734 -2.51180 1.43691
9 0.02702 1.24621 -185.44737 -2.72570 1.72278
9 0.02702 1.25200 -185.44737 -2.74049 1.66486
9 0.02702 0.99755 -185.44737 -2.75724 1.18224
10 0.03027 1.46211 -185.44738 -2.46071 2.62220
10 0.03027 1.11654 -185.44738 -2.48559 1.25511
10 0.03027 0.54660 -185.44738 -2.50170 1.26064
11 0.03601 0.75726 -185.44741 -2.29287 0.72642
12 0.03099 0.72117 -185.44741 -2.37345 1.82475
13 0.03214 0.97221 -185.44742 -2.28763 1.11205
14 0.03305 0.75182 -185.44744 -2.30235 1.14657
15 0.02478 3.72830 -185.44746 -2.12643 5.07223
15 0.02478 3.88532 -185.44746 -2.21729 4.57005
15 0.02478 1.06466 -185.44746 -2.42117 1.46295
15 0.02478 0.60485 -185.44746 -2.47843 0.77072
16 0.01861 0.65525 -185.44749 -2.40462 1.27356
17 0.03192 0.87106 -185.44752 -2.41333 1.25081
18 0.01829 1.04055 -185.44750 -2.32356 1.07917
18 0.01829 0.67217 -185.44750 -2.36294 0.82032
19 0.01417 0.68694 -185.44751 -2.41045 0.82854
20 0.01179 0.63145 -185.44753 -2.37695 1.01262
21 0.00904 --- -185.44751 --- ---

Sounds good; what was the solution? Your initial parameters looked pretty reasonable.