# SCF not converging during RHF/STO-3G geometry optimisation

I'm new in the field of QM methods and I've run into a problem for which I can't find a solution online.

I have tried with different basis sets, I've raised the maximum number of iterations and number of steps, changed the gradient convergence criteria, mixed up coordinates of atoms, tried different optimization methods, etc. Nothing worked.

I've previously minimized the structure using UFF and MMFF94s in Avogadro.

I'll paste the input text. Any help would be appreciated!

File created by the GAMESS Input Deck Generator Plugin for Avogadro:

 $$BASIS GBASIS=STO NGAUSS=3$$END
$$CONTRL SCFTYP=RHF RUNTYP=OPTIMIZE MULT=1 ICHARG=3$$END
$$STATPT OPTTOL=0.0005 NSTEP=200$$END
$$SYSTEM TIMLIM=525600 MEMORY=30000000 PARALL=.TRUE.$$END

$$DATA Title C1 C 6.0 0.44525 -3.16984 0.69612 C 6.0 1.01573 -4.03321 1.61274 C 6.0 2.41072 -3.80725 1.61097 C 6.0 2.67608 -2.82362 0.67533 N 7.0 1.45795 -2.36971 0.21750 C 6.0 3.90546 -2.34686 0.10991 C 6.0 4.05712 -1.04579 -0.23679 C 6.0 5.21540 -0.44191 -0.85574 C 6.0 5.05403 0.87344 -0.99275 C 6.0 3.70858 1.06810 -0.43356 N 7.0 3.13224 -0.03282 -0.03960 C 6.0 3.16875 2.46275 -0.34431 C 6.0 1.83356 2.65144 -0.33629 C 6.0 1.15168 3.94223 -0.27795 C 6.0 -0.17973 3.74202 -0.29816 C 6.0 -0.44459 2.30513 -0.36740 N 7.0 0.80858 1.73703 -0.38199 C 6.0 -1.66025 1.72152 -0.50118 C 6.0 -1.74252 0.22603 -0.45510 C 6.0 -2.99115 -0.38252 -0.93654 C 6.0 -2.74372 -1.67799 -0.75080 C 6.0 -1.41952 -1.88040 -0.19917 N 7.0 -0.83234 -0.62964 -0.07998 C 6.0 -0.88336 -3.06808 0.16991 H 1.0 0.48692 -4.78481 2.18676 H 1.0 3.14281 -4.35524 2.19072 H 1.0 1.32408 -1.59926 -0.42603 H 1.0 6.09460 -0.97630 -1.18243 H 1.0 5.71915 1.59050 -1.43500 H 1.0 1.62190 4.91198 -0.23985 H 1.0 -0.91995 4.52597 -0.27506 H 1.0 0.95387 0.73081 -0.31926 H 1.0 -3.86702 0.07728 -1.35203 H 1.0 -3.43575 -2.47239 -0.99291 C 6.0 5.01165 -3.32684 -0.09860 C 6.0 4.80323 -4.43424 -0.92915 C 6.0 6.92926 -5.30155 -0.40954 C 6.0 6.21677 -3.24050 0.60124 C 6.0 7.18305 -4.22849 0.43747 C 6.0 5.48783 -6.55588 -1.93242 N 7.0 5.75586 -5.38564 -1.07564 H 1.0 6.43367 -6.93986 -2.32293 H 1.0 4.85110 -6.24747 -2.76568 H 1.0 4.98761 -7.30560 -1.31455 C 6.0 4.09828 3.60885 -0.24634 C 6.0 4.66088 3.95246 0.98833 C 6.0 4.41857 4.37817 -1.36593 C 6.0 5.28427 5.45895 -1.23237 N 7.0 5.50715 5.00575 1.09501 C 6.0 5.81916 5.75962 0.01557 C 6.0 -2.90380 2.52166 -0.34897 C 6.0 -3.66129 2.56849 0.82733 N 7.0 -4.81632 3.27544 0.88045 C 6.0 -5.27208 3.94587 -0.20273 C 6.0 -3.36321 3.21702 -1.46861 C 6.0 -4.55383 3.93261 -1.39330 C 6.0 -5.60984 3.29056 2.12518 H 1.0 -6.11974 4.25361 2.21048 H 1.0 -4.94027 3.15848 2.97883 H 1.0 -6.32923 2.47041 2.06314 C 6.0 -1.71894 -4.29132 0.03909 C 6.0 -1.71807 -5.02753 -1.14744 C 6.0 -2.51092 -6.17434 -1.26052 C 6.0 -3.31052 -6.61750 -0.19482 C 6.0 -3.30480 -5.87783 0.98628 C 6.0 -2.51580 -4.72439 1.10405 N 7.0 -4.05948 -7.78149 -0.43353 C 6.0 -4.89310 -8.55874 0.31080 C 6.0 -5.16776 -8.28274 1.75727 H 1.0 -4.23558 -8.26628 2.32654 H 1.0 -5.79022 -9.08611 2.16452 H 1.0 -5.71925 -7.34591 1.86399 O 8.0 -5.42168 -9.52251 -0.25008 C 6.0 6.07588 5.36035 2.41047 H 1.0 5.41546 6.10513 2.86119 H 1.0 7.08124 5.76404 2.26527 H 1.0 6.13218 4.46273 3.03142 H 1.0 -3.99409 -8.17283 -1.36812 H 1.0 3.86903 -4.58358 -1.46487 H 1.0 8.12201 -4.17578 0.98576 H 1.0 7.65002 -6.10332 -0.54924 H 1.0 6.39871 -2.42357 1.29876 H 1.0 4.43770 3.40075 1.89831 H 1.0 5.53797 6.07004 -2.09755 H 1.0 6.49265 6.60082 0.16210 H 1.0 3.99352 4.14840 -2.34365 H 1.0 -3.36137 2.04034 1.72923 H 1.0 -6.21197 4.48444 -0.10738 H 1.0 -4.92606 4.47294 -2.26256 H 1.0 -2.80635 3.19914 -2.40612 H 1.0 -2.52664 -4.17043 2.04095 H 1.0 -1.10653 -4.71768 -1.99108 H 1.0 -2.49054 -6.72496 -2.19955 H 1.0 -3.89964 -6.14606 1.84813$$END


Here's the part of my output file that is SCF-related:

          --------------------------
RHF SCF CALCULATION
--------------------------

NUCLEAR ENERGY =      6789.1338849966
MAXIT =   30     NPUNCH=    2
EXTRAP=T  DAMP=F  SHIFT=F  RSTRCT=F  DIIS=F  DEM=F  SOSCF=T
DENSITY MATRIX CONV=  1.00E-05
SOSCF WILL OPTIMIZE   23688 ORBITAL ROTATIONS, SOGTOL=   0.250
MEMORY REQUIRED FOR RHF ITERS=    819320 WORDS.

ITER EX DEM     TOTAL ENERGY        E CHANGE  DENSITY CHANGE     ORB. GRAD
1  0  0    -2243.0902254864 -2243.0902254864   0.641974797   0.000000000
---------------START SECOND ORDER SCF---------------
2  1  0    -2246.0402678439    -2.9500423574   0.296673768   0.098393134
3  2  0    -2246.1780346977    -0.1377668539   0.918798210   0.089555764
4  3  0    -2241.9109382429     4.2670964549   0.915303672   0.282318567
5  4  0    -2246.1174690545    -4.2065308116   0.604249079   0.121159545
6  5  0    -2246.0432278272     0.0742412273   0.579402296   0.238306637
7  6  0    -2246.2092437253    -0.1660158981   0.609110594   0.117220258
8  7  0    -2245.4738991800     0.7353445453   0.785785223   0.390438537
9  8  0    -2245.8285426085    -0.3546434285   0.475649688   0.134490303
10  9  0    -2246.1021152737    -0.2735726652   0.587216948   0.144268895
11 10  0    -2245.0340885624     1.0680267113   0.657495276   0.408934150
12 11  0    -2246.1749635724    -1.1408750100   0.231319789   0.081220026
13 12  0    -2246.2480160025    -0.0730524302   0.204610410   0.066506475
14 13  0    -2246.2658401926    -0.0178241901   0.172142881   0.079471677
15 14  0    -2246.2873580939    -0.0215179013   0.161126202   0.059525949
16 15  0    -2246.3210293981    -0.0336713042   0.056114250   0.022848617
17 16  0    -2246.3305780028    -0.0095486047   0.041231998   0.012283754
18 17  0    -2246.3305121964     0.0000658064   0.021626233   0.014104884
19 18  0    -2246.3330591814    -0.0025469850   0.015124765   0.004783815
20 19  0    -2246.3332910450    -0.0002318636   0.010371230   0.003217253
21 20  0    -2246.3334251468    -0.0001341018   0.007962098   0.002766804
22 21  0    -2246.3335199835    -0.0000948366   0.005375285   0.001779536
23 22  0    -2246.3335639378    -0.0000439543   0.003552000   0.000853716
24 23  0    -2246.3335616981     0.0000022397   0.002276108   0.001140585
25 24  0    -2246.3335762709    -0.0000145729   0.000648266   0.000186249
26 25  0    -2246.3335762326     0.0000000384   0.000442354   0.000284347
27 26  0    -2246.3335769845    -0.0000007519   0.000249739   0.000058733
28 27  0    -2246.3335769710     0.0000000135   0.000146064   0.000083809
29 28  0    -2246.3335770730    -0.0000001019   0.000094133   0.000024011
30 29  0    -2246.3335770721     0.0000000008   0.000046691   0.000031845

SCF IS UNCONVERGED, TOO MANY ITERATIONS
TIME TO FORM FOCK OPERATORS=       1.4 SECONDS (       0.0 SEC/ITER)
TIME TO SOLVE SCF EQUATIONS=       0.4 SECONDS (       0.0 SEC/ITER)

FINAL RHF ENERGY IS        0.0000000000 AFTER  30 ITERATIONS
$$$$

• And to model successfully two molecules in one model (here, triple charged porphyrin and a molecule of water) is just an additional complication better to postpone for a later step. Aug 19, 2021 at 20:35
• Lost in migration from chemistry.se: The input coordinates still are flat 2D ($z = 0$ for all atoms) thus unlikely result of running MMFF96 successfully (where one anticipates at least some variation for $z$) and incomplete (no hydrogens at all). I suggest to resolve these issues in first place. Aug 19, 2021 at 20:59
• +1 and welcome to our new community! Hopefully we'll be able to help you, and hopefully we can see more of you in the future! I've changed RHF to UHF in your title because that's what your input file says (feel free to change it back if you want). Also, please show us the output file of the case that came closest to convergence. As long as it's fewer than about 30,000 characters it should be fine. If it's longer than that you can upload it here in a folder called 6594 since that's the number in this question's URL. Aug 19, 2021 at 21:15
• Is the SCF step you are showing the initial one or is it after a few optimization steps? It looks like the SCF just needs a few more steps. Both the energy and density differences are dropping with each iteration. GAMESS uses a default threshold of 1e-5 for density convergence and in your case this ~5e-5. I suspect the orbital gradient threshold is similar. I think just adding a few more SCF iterations should resolve your issue.
– Tyberius
Aug 20, 2021 at 13:59
• How did you get the initial structure? Assembled by hand, or got it from a crystal structure database? It has several rotatable bonds. If you assembled the structure by hand, did you try a conformer search before submiting to Gamess? Aug 21, 2021 at 1:02

## 2 Answers

If you look at your last five iterations, you will see that the density change (which is what matters most for SCF convergence) is getting smaller in each iteration, meaning that the calculation is still converging, and will converge if you give it more iterations:

Iteration SCF Energy Energy change Density Change
26 -2246.3335762326 0.0000000384 0.000442354
27 -2246.3335769845 -0.0000007519 0.000249739
28 -2246.3335769710 0.0000000135 0.000146064
29 -2246.3335770730 -0.0000001019 0.000094133
30 -2246.3335770721 0.0000000008 0.000046691

You just have to increase the maximum number of iterations beyond the default value of 30.

Based on your input file, I tried to run the calculation in my machine. As you didn't specified how did you obtain the original structure (assembled by hand or downloaded from structure database), I first generated a SDF file of your structure with Avogadro, and did a conformer search with obconformer from Open Babel, just to be sure to pick a initial conformation close to a global minimum:

obconformer 2000 100 C46H39N8O.sdf > C46H39N8O_best_conformer.sdf


Then I created a input file similar to yours, but replacing the atomic coordinates with those of the best conformer I could find, and adding the line " \$SCF DIRSCF=.TRUE. \$END", just to avoid heavy disk load as discussed in another question here. So my first modified input file was as shown bellow:

 $$BASIS GBASIS=STO NGAUSS=3$$END
$$CONTRL SCFTYP=RHF RUNTYP=OPTIMIZE MULT=1 ICHARG=3$$END
$$STATPT OPTTOL=0.0005 NSTEP=200$$END
$$SYSTEM TIMLIM=525600 MEMORY=30000000 PARALL=.TRUE.$$END
$$SCF DIRSCF=.TRUE.$$END

$$DATA Title C1 C 6.0 0.41860 -3.30490 0.31600 C 6.0 1.10200 -4.52370 0.73380 C 6.0 2.42450 -4.28410 0.78380 C 6.0 2.67500 -2.89250 0.39540 N 7.0 1.41990 -2.36510 0.23560 C 6.0 3.89300 -2.34610 0.20370 C 6.0 4.00810 -0.89640 -0.17300 C 6.0 5.30160 -0.40640 -0.68190 C 6.0 5.05870 0.89400 -0.83740 C 6.0 3.70420 1.21910 -0.44440 N 7.0 3.08680 0.02710 -0.09330 C 6.0 3.16320 2.46290 -0.38800 C 6.0 1.78790 2.65610 -0.01270 C 6.0 1.14300 3.71600 0.59850 C 6.0 -0.24560 3.46160 0.55600 C 6.0 -0.44080 2.24970 -0.08490 N 7.0 0.81320 1.72900 -0.32930 C 6.0 -1.63850 1.60250 -0.55470 C 6.0 -1.72630 0.25390 -0.68420 C 6.0 -2.86790 -0.47210 -1.20130 C 6.0 -2.73200 -1.78180 -1.01290 C 6.0 -1.40480 -1.84960 -0.38790 N 7.0 -0.80540 -0.69210 -0.27150 C 6.0 -0.89590 -3.18980 0.04360 H 1.0 0.62760 -5.46160 0.97420 H 1.0 3.17890 -4.99650 1.07840 H 1.0 1.24780 -1.39800 -0.02880 H 1.0 6.20030 -0.95600 -0.88630 H 1.0 5.77840 1.60660 -1.21090 H 1.0 1.62360 4.60840 0.97960 H 1.0 -1.03010 4.12500 0.89730 H 1.0 0.99550 0.81810 -0.73260 H 1.0 -3.72340 -0.01020 -1.67100 H 1.0 -3.39930 -2.57860 -1.27710 C 6.0 5.09930 -3.17940 0.24060 C 6.0 5.33760 -4.21240 -0.76950 C 6.0 7.34990 -4.84480 0.33370 C 6.0 6.01250 -3.04610 1.22980 C 6.0 7.19050 -3.89900 1.27580 C 6.0 6.57730 -6.17400 -1.61860 N 7.0 6.45010 -5.03620 -0.71060 H 1.0 7.62650 -6.36620 -1.86580 H 1.0 6.04580 -5.99540 -2.56060 H 1.0 6.15630 -7.07230 -1.15420 C 6.0 4.00990 3.64960 -0.68460 C 6.0 5.15900 4.03920 0.13990 C 6.0 3.70200 4.45190 -1.73110 C 6.0 4.48900 5.63560 -2.03240 N 7.0 5.93110 5.15330 -0.17120 C 6.0 5.54380 5.93410 -1.25720 C 6.0 -2.82270 2.44170 -0.86750 C 6.0 -2.82510 3.44000 -1.93690 N 7.0 -3.95940 4.19450 -2.21580 C 6.0 -5.08590 4.00550 -1.41900 C 6.0 -3.94570 2.33460 -0.11600 C 6.0 -5.12750 3.12490 -0.40690 C 6.0 -3.91230 5.27840 -3.19350 H 1.0 -4.88250 5.40460 -3.68690 H 1.0 -3.17110 5.08010 -3.97540 H 1.0 -3.65020 6.21960 -2.69830 C 6.0 -1.80030 -4.35770 0.16170 C 6.0 -2.46430 -4.61430 1.36570 C 6.0 -3.29040 -5.73860 1.50590 C 6.0 -3.47450 -6.62770 0.44370 C 6.0 -2.81370 -6.36800 -0.76480 C 6.0 -1.98080 -5.24840 -0.90450 N 7.0 -4.28310 -7.78400 0.51290 C 6.0 -5.00990 -8.24260 1.59660 C 6.0 -5.75030 -9.52020 1.29710 H 1.0 -6.48430 -9.35060 0.50470 H 1.0 -6.27980 -9.85850 2.19530 H 1.0 -5.04800 -10.30200 0.99580 O 8.0 -5.08920 -7.71850 2.70470 C 6.0 6.99280 5.59990 0.72850 H 1.0 6.58200 6.27190 1.48970 H 1.0 7.77730 6.13550 0.18170 H 1.0 7.46870 4.75240 1.23410 H 1.0 -4.33120 -8.34650 -0.32950 H 1.0 4.61530 -4.40300 -1.55610 H 1.0 7.90580 -3.76690 2.07770 H 1.0 8.20090 -5.51870 0.34110 H 1.0 5.89450 -2.31560 2.02460 H 1.0 5.42530 3.48250 1.03100 H 1.0 4.19970 6.26210 -2.86720 H 1.0 6.15030 6.81630 -1.43690 H 1.0 2.84840 4.24770 -2.36970 H 1.0 -1.92590 3.65640 -2.50250 H 1.0 -5.94130 4.62570 -1.66740 H 1.0 -6.01410 2.98860 0.19980 H 1.0 -4.00490 1.64550 0.72110 H 1.0 -1.46770 -5.08290 -1.85000 H 1.0 -2.33390 -3.94840 2.21780 H 1.0 -3.77150 -5.89310 2.46710 H 1.0 -2.92930 -7.03750 -1.61360$$END


But then I ran into the same error you encountered, failure to converge SCF:

...... END OF PROPERTY EVALUATION ......
CPU     0: STEP CPU TIME=     0.12 TOTAL CPU TIME=         79.1 (      1.3 MIN)
TOTAL WALL CLOCK TIME=         80.3 SECONDS, CPU UTILIZATION IS    98.56%

***** FAILURE TO LOCATE STATIONARY POINT, SCF HAS NOT CONVERGED
UPDATED HESSIAN, GEOMETRY, AND VECTORS WILL BE PUNCHED FOR RESTART
EXECUTION OF GAMESS TERMINATED -ABNORMALLY- AT 10:44:44 27-AUG-2021
1154292  WORDS OF DYNAMIC MEMORY USED
CPU     0: STEP CPU TIME=     0.00 TOTAL CPU TIME=         79.1 (      1.3 MIN)
TOTAL WALL CLOCK TIME=         80.3 SECONDS, CPU UTILIZATION IS    98.54%
DDI Process 0: error code 911
ddikick.x: application process 0 quit unexpectedly.
ddikick.x: Fatal error detected.
The error is most likely to be in the application, so check for
input errors, disk space, memory needs, application bugs, etc.
ddikick.x will now clean up all processes, and exit...
DDI Process 2: terminated upon request.
DDI Process 1: terminated upon request.
ddikick.x: Sending kill signal to DDI processes.
ddikick.x: Execution terminated due to error(s).
unset echo
----- accounting info -----
Files used on the master node user-PC were:
-rw-rw-r-- 1 user user     3996 ago 27 10:43 /tmp/C46H39N8O_best_conformer.F05
-rw-rw-r-- 1 user user 10143200 ago 27 10:44 /tmp/C46H39N8O_best_conformer.F10
ls: No match.
ls: No match.
ls: No match.
sex 27 ago 2021 10:44:46 -03
0.112u 0.032s 1:22.91 0.1%  0+0k 2768+24io 13pf+0w


In my second attempt I followed the advice given by @NikeDattani in his answer, increasing the maximum number of SCF cycles by adding MAXIT=60 to the \$CONTRL group, what doubles the limit, from the default (30):  $$BASIS GBASIS=STO NGAUSS=3$$END $$CONTRL SCFTYP=RHF RUNTYP=OPTIMIZE MULT=1 ICHARG=3 MAXIT=60$$END $$STATPT OPTTOL=0.0005 NSTEP=200$$END $$SYSTEM TIMLIM=525600 MEMORY=30000000 PARALL=.TRUE.$$END $$SCF DIRSCF=.TRUE.$$END $$DATA Title C1 C 6.0 0.41860 -3.30490 0.31600 C 6.0 1.10200 -4.52370 0.73380 C 6.0 2.42450 -4.28410 0.78380 C 6.0 2.67500 -2.89250 0.39540 N 7.0 1.41990 -2.36510 0.23560 C 6.0 3.89300 -2.34610 0.20370 C 6.0 4.00810 -0.89640 -0.17300 C 6.0 5.30160 -0.40640 -0.68190 C 6.0 5.05870 0.89400 -0.83740 C 6.0 3.70420 1.21910 -0.44440 N 7.0 3.08680 0.02710 -0.09330 C 6.0 3.16320 2.46290 -0.38800 C 6.0 1.78790 2.65610 -0.01270 C 6.0 1.14300 3.71600 0.59850 C 6.0 -0.24560 3.46160 0.55600 C 6.0 -0.44080 2.24970 -0.08490 N 7.0 0.81320 1.72900 -0.32930 C 6.0 -1.63850 1.60250 -0.55470 C 6.0 -1.72630 0.25390 -0.68420 C 6.0 -2.86790 -0.47210 -1.20130 C 6.0 -2.73200 -1.78180 -1.01290 C 6.0 -1.40480 -1.84960 -0.38790 N 7.0 -0.80540 -0.69210 -0.27150 C 6.0 -0.89590 -3.18980 0.04360 H 1.0 0.62760 -5.46160 0.97420 H 1.0 3.17890 -4.99650 1.07840 H 1.0 1.24780 -1.39800 -0.02880 H 1.0 6.20030 -0.95600 -0.88630 H 1.0 5.77840 1.60660 -1.21090 H 1.0 1.62360 4.60840 0.97960 H 1.0 -1.03010 4.12500 0.89730 H 1.0 0.99550 0.81810 -0.73260 H 1.0 -3.72340 -0.01020 -1.67100 H 1.0 -3.39930 -2.57860 -1.27710 C 6.0 5.09930 -3.17940 0.24060 C 6.0 5.33760 -4.21240 -0.76950 C 6.0 7.34990 -4.84480 0.33370 C 6.0 6.01250 -3.04610 1.22980 C 6.0 7.19050 -3.89900 1.27580 C 6.0 6.57730 -6.17400 -1.61860 N 7.0 6.45010 -5.03620 -0.71060 H 1.0 7.62650 -6.36620 -1.86580 H 1.0 6.04580 -5.99540 -2.56060 H 1.0 6.15630 -7.07230 -1.15420 C 6.0 4.00990 3.64960 -0.68460 C 6.0 5.15900 4.03920 0.13990 C 6.0 3.70200 4.45190 -1.73110 C 6.0 4.48900 5.63560 -2.03240 N 7.0 5.93110 5.15330 -0.17120 C 6.0 5.54380 5.93410 -1.25720 C 6.0 -2.82270 2.44170 -0.86750 C 6.0 -2.82510 3.44000 -1.93690 N 7.0 -3.95940 4.19450 -2.21580 C 6.0 -5.08590 4.00550 -1.41900 C 6.0 -3.94570 2.33460 -0.11600 C 6.0 -5.12750 3.12490 -0.40690 C 6.0 -3.91230 5.27840 -3.19350 H 1.0 -4.88250 5.40460 -3.68690 H 1.0 -3.17110 5.08010 -3.97540 H 1.0 -3.65020 6.21960 -2.69830 C 6.0 -1.80030 -4.35770 0.16170 C 6.0 -2.46430 -4.61430 1.36570 C 6.0 -3.29040 -5.73860 1.50590 C 6.0 -3.47450 -6.62770 0.44370 C 6.0 -2.81370 -6.36800 -0.76480 C 6.0 -1.98080 -5.24840 -0.90450 N 7.0 -4.28310 -7.78400 0.51290 C 6.0 -5.00990 -8.24260 1.59660 C 6.0 -5.75030 -9.52020 1.29710 H 1.0 -6.48430 -9.35060 0.50470 H 1.0 -6.27980 -9.85850 2.19530 H 1.0 -5.04800 -10.30200 0.99580 O 8.0 -5.08920 -7.71850 2.70470 C 6.0 6.99280 5.59990 0.72850 H 1.0 6.58200 6.27190 1.48970 H 1.0 7.77730 6.13550 0.18170 H 1.0 7.46870 4.75240 1.23410 H 1.0 -4.33120 -8.34650 -0.32950 H 1.0 4.61530 -4.40300 -1.55610 H 1.0 7.90580 -3.76690 2.07770 H 1.0 8.20090 -5.51870 0.34110 H 1.0 5.89450 -2.31560 2.02460 H 1.0 5.42530 3.48250 1.03100 H 1.0 4.19970 6.26210 -2.86720 H 1.0 6.15030 6.81630 -1.43690 H 1.0 2.84840 4.24770 -2.36970 H 1.0 -1.92590 3.65640 -2.50250 H 1.0 -5.94130 4.62570 -1.66740 H 1.0 -6.01410 2.98860 0.19980 H 1.0 -4.00490 1.64550 0.72110 H 1.0 -1.46770 -5.08290 -1.85000 H 1.0 -2.33390 -3.94840 2.21780 H 1.0 -3.77150 -5.89310 2.46710 H 1.0 -2.92930 -7.03750 -1.61360$$END  With this I was able to finish the calculation successfully. The first SCF cycle took 35 iterations to converge, a bit over the default limit: ......END OF GEOMETRY SEARCH...... CPU 0: STEP CPU TIME= 0.08 TOTAL CPU TIME= 2025.0 ( 33.8 MIN) TOTAL WALL CLOCK TIME= 2046.8 SECONDS, CPU UTILIZATION IS 98.94% 1154292 WORDS OF DYNAMIC MEMORY USED EXECUTION OF GAMESS TERMINATED NORMALLY 11:36:53 27-AUG-2021 DDI: 263640 bytes (0.3 MB / 0 MWords) used by master data server. ---------------------------------------- CPU timing information for all processes ======================================== 0: 2016.668 + 8.342 = 2025.10 1: 2009.392 + 8.384 = 2017.776 2: 2010.217 + 6.687 = 2016.905 ---------------------------------------- ddikick.x: exited gracefully. unset echo ----- accounting info ----- Files used on the master node user-PC were: -rw-rw-r-- 1 user user 4005 ago 27 11:02 /tmp/C46H39N8O_best_conformer_scf60.F05 -rw-rw-r-- 1 user user 10241360 ago 27 11:36 /tmp/C46H39N8O_best_conformer_scf60.F10 ls: No match. ls: No match. ls: No match. sex 27 ago 2021 11:36:56 -03 0.123u 0.010s 34:09.93 0.0% 0+0k 0+32io 0pf+0w  The optimized geometry I found is shown bellow:  ***** EQUILIBRIUM GEOMETRY LOCATED ***** COORDINATES OF ALL ATOMS ARE (ANGS) ATOM CHARGE X Y Z ------------------------------------------------------------ C 6.0 0.4670707680 -3.3552994825 0.1507280614 C 6.0 1.1588544563 -4.6338783718 0.4445871557 C 6.0 2.4689515383 -4.4395943535 0.4541873257 C 6.0 2.7562370062 -3.0091345193 0.1743635960 N 7.0 1.5156307238 -2.4081016375 0.0266144568 C 6.0 3.9719116669 -2.4023232928 0.0699346952 C 6.0 4.1405832586 -0.9644046019 -0.1600003936 C 6.0 5.4756194557 -0.3454977898 -0.4364880003 C 6.0 5.2790151208 0.9487939050 -0.5948465975 C 6.0 3.8224457041 1.1994350671 -0.4111569799 N 7.0 3.1653624898 -0.0733429468 -0.1746656501 C 6.0 3.2131860874 2.4010969967 -0.4378266471 C 6.0 1.7672389380 2.6554884179 -0.3133471273 C 6.0 1.1332781145 3.8551546052 -0.0713582931 C 6.0 -0.2507525509 3.6384497899 -0.1139104189 C 6.0 -0.4682879581 2.3055153479 -0.3838216106 N 7.0 0.7750275545 1.7027871421 -0.4979505168 C 6.0 -1.7468027986 1.5998399162 -0.5865430539 C 6.0 -1.9116339609 0.2647953389 -0.5994588091 C 6.0 -3.1821261231 -0.4763219558 -0.8388994600 C 6.0 -2.9257325274 -1.7565880622 -0.6544317854 C 6.0 -1.4716213631 -1.8669966678 -0.3121022621 N 7.0 -0.8590506810 -0.7022080072 -0.3165959982 C 6.0 -0.8541201662 -3.1777547335 -0.0061204650 H 1.0 0.6291084008 -5.5607129561 0.6224905515 H 1.0 3.2311470499 -5.1734400558 0.6576256324 H 1.0 1.3887951614 -1.4034432947 -0.0961927507 H 1.0 6.4056173353 -0.8859732005 -0.5168353875 H 1.0 6.0133099933 1.7000523593 -0.8377011545 H 1.0 1.6154633754 4.7976054509 0.1285275782 H 1.0 -1.0098946530 4.3833914876 0.0530459525 H 1.0 0.9215494399 0.6929455612 -0.5952873091 H 1.0 -4.1176741983 -0.0238319094 -1.1255705275 H 1.0 -3.5951921601 -2.6001830701 -0.7402330786 C 6.0 5.2062931648 -3.2539791268 0.1968439888 C 6.0 5.4345540416 -4.2996656313 -0.6881651055 C 6.0 7.4564151939 -4.9104627605 0.3962751372 C 6.0 6.1715756891 -3.0573006214 1.2012524545 C 6.0 7.2900117884 -3.8794176402 1.2991235245 C 6.0 6.7075649458 -6.2571245757 -1.5522415989 N 7.0 6.5324185192 -5.1115755044 -0.5894160954 H 1.0 7.7716647339 -6.3907547483 -1.7452654634 H 1.0 6.1855611903 -6.0173075948 -2.4773936225 H 1.0 6.2885912437 -7.1618015633 -1.1048650881 C 6.0 4.0351172403 3.6556082505 -0.6671988984 C 6.0 5.0705942148 4.0202936679 0.1769952752 C 6.0 3.7622782712 4.5050886825 -1.7549623535 C 6.0 4.5118858743 5.6548011229 -1.9746306092 N 7.0 5.8148660896 5.1507795630 -0.0456114931 C 6.0 5.5410466764 5.9655184978 -1.1067795480 C 6.0 -2.9513482825 2.4931116417 -0.8040307568 C 6.0 -2.9560562783 3.4260904715 -1.8297332327 N 7.0 -4.0348848243 4.2347357727 -2.0632659425 C 6.0 -5.1515451254 4.1458524398 -1.2778204428 C 6.0 -4.0992511240 2.4185675772 0.0024204078 C 6.0 -5.1984888766 3.2399670026 -0.2384935236 C 6.0 -3.9872304236 5.2568474916 -3.1689140647 H 1.0 -4.9688732350 5.3074177934 -3.6405070772 H 1.0 -3.2373700226 4.9493588835 -3.8957744772 H 1.0 -3.7250311799 6.2272056385 -2.7404039003 C 6.0 -1.7796374651 -4.3696310302 0.1289365796 C 6.0 -2.4851314791 -4.5928304737 1.3084203425 C 6.0 -3.3227346391 -5.6822895359 1.4495100316 C 6.0 -3.4807749020 -6.5863546324 0.3923217964 C 6.0 -2.7794390275 -6.3593149327 -0.7984059247 C 6.0 -1.9420651035 -5.2692015437 -0.9215120564 N 7.0 -4.3303193356 -7.7167938506 0.4780566884 C 6.0 -5.0441563383 -8.1844319953 1.6296607490 C 6.0 -5.7966048821 -9.5013881185 1.3551089539 H 1.0 -6.5125343745 -9.3647235413 0.5491391298 H 1.0 -6.3232601112 -9.8056646733 2.2533226070 H 1.0 -5.0965328402 -10.2824153924 1.0714207460 O 8.0 -5.0495580137 -7.5930429013 2.6938406681 C 6.0 6.9223323747 5.5243219559 0.9064200048 H 1.0 6.5230737524 6.1983745084 1.6677805024 H 1.0 7.7118231089 6.0198094112 0.3411000509 H 1.0 7.3056035494 4.6157354939 1.3685263928 H 1.0 -4.3588141998 -8.3149668203 -0.3458960881 H 1.0 4.7524718717 -4.5278223370 -1.5042538440 H 1.0 8.0295458045 -3.7349956645 2.0782600222 H 1.0 8.3030442874 -5.5955645782 0.4190807020 H 1.0 6.0369991829 -2.2532588197 1.9211273287 H 1.0 5.3458015582 3.4378444187 1.0540054726 H 1.0 4.3086212165 6.3105131733 -2.8136498157 H 1.0 6.1691685170 6.8493372179 -1.2191039501 H 1.0 2.9523433434 4.2538428125 -2.4358062564 H 1.0 -2.1092162398 3.5600091100 -2.4988273991 H 1.0 -5.9725452929 4.8204810613 -1.5208509855 H 1.0 -6.0895834320 3.1828816102 0.3768112030 H 1.0 -4.1294840212 1.7114112541 0.8288813738 H 1.0 -1.4078347920 -5.1149991579 -1.8511763110 H 1.0 -2.3732586854 -3.9059428186 2.1390277103 H 1.0 -3.8595693161 -5.8529255892 2.3709361837 H 1.0 -2.8980480782 -7.0470788280 -1.6247108319  As your molecule has a charge of +3, I also tested starting a run including solvation effects, instead of increasing MAXIT, by including the line " \$PCM SOLVNT=H2O \\$END" in your original input file, as shown bellow:

 $$BASIS GBASIS=STO NGAUSS=3$$END
$$CONTRL SCFTYP=RHF RUNTYP=OPTIMIZE MULT=1 ICHARG=3$$END
$$STATPT OPTTOL=0.0005 NSTEP=200$$END
$$SYSTEM TIMLIM=525600 MEMORY=30000000 PARALL=.TRUE.$$END
$$SCF DIRSCF=.TRUE.$$END
$$PCM SOLVNT=H2O$$END

$$DATA Title C1 C 6.0 0.44525 -3.16984 0.69612 C 6.0 1.01573 -4.03321 1.61274 C 6.0 2.41072 -3.80725 1.61097 C 6.0 2.67608 -2.82362 0.67533 N 7.0 1.45795 -2.36971 0.21750 C 6.0 3.90546 -2.34686 0.10991 C 6.0 4.05712 -1.04579 -0.23679 C 6.0 5.21540 -0.44191 -0.85574 C 6.0 5.05403 0.87344 -0.99275 C 6.0 3.70858 1.06810 -0.43356 N 7.0 3.13224 -0.03282 -0.03960 C 6.0 3.16875 2.46275 -0.34431 C 6.0 1.83356 2.65144 -0.33629 C 6.0 1.15168 3.94223 -0.27795 C 6.0 -0.17973 3.74202 -0.29816 C 6.0 -0.44459 2.30513 -0.36740 N 7.0 0.80858 1.73703 -0.38199 C 6.0 -1.66025 1.72152 -0.50118 C 6.0 -1.74252 0.22603 -0.45510 C 6.0 -2.99115 -0.38252 -0.93654 C 6.0 -2.74372 -1.67799 -0.75080 C 6.0 -1.41952 -1.88040 -0.19917 N 7.0 -0.83234 -0.62964 -0.07998 C 6.0 -0.88336 -3.06808 0.16991 H 1.0 0.48692 -4.78481 2.18676 H 1.0 3.14281 -4.35524 2.19072 H 1.0 1.32408 -1.59926 -0.42603 H 1.0 6.09460 -0.97630 -1.18243 H 1.0 5.71915 1.59050 -1.43500 H 1.0 1.62190 4.91198 -0.23985 H 1.0 -0.91995 4.52597 -0.27506 H 1.0 0.95387 0.73081 -0.31926 H 1.0 -3.86702 0.07728 -1.35203 H 1.0 -3.43575 -2.47239 -0.99291 C 6.0 5.01165 -3.32684 -0.09860 C 6.0 4.80323 -4.43424 -0.92915 C 6.0 6.92926 -5.30155 -0.40954 C 6.0 6.21677 -3.24050 0.60124 C 6.0 7.18305 -4.22849 0.43747 C 6.0 5.48783 -6.55588 -1.93242 N 7.0 5.75586 -5.38564 -1.07564 H 1.0 6.43367 -6.93986 -2.32293 H 1.0 4.85110 -6.24747 -2.76568 H 1.0 4.98761 -7.30560 -1.31455 C 6.0 4.09828 3.60885 -0.24634 C 6.0 4.66088 3.95246 0.98833 C 6.0 4.41857 4.37817 -1.36593 C 6.0 5.28427 5.45895 -1.23237 N 7.0 5.50715 5.00575 1.09501 C 6.0 5.81916 5.75962 0.01557 C 6.0 -2.90380 2.52166 -0.34897 C 6.0 -3.66129 2.56849 0.82733 N 7.0 -4.81632 3.27544 0.88045 C 6.0 -5.27208 3.94587 -0.20273 C 6.0 -3.36321 3.21702 -1.46861 C 6.0 -4.55383 3.93261 -1.39330 C 6.0 -5.60984 3.29056 2.12518 H 1.0 -6.11974 4.25361 2.21048 H 1.0 -4.94027 3.15848 2.97883 H 1.0 -6.32923 2.47041 2.06314 C 6.0 -1.71894 -4.29132 0.03909 C 6.0 -1.71807 -5.02753 -1.14744 C 6.0 -2.51092 -6.17434 -1.26052 C 6.0 -3.31052 -6.61750 -0.19482 C 6.0 -3.30480 -5.87783 0.98628 C 6.0 -2.51580 -4.72439 1.10405 N 7.0 -4.05948 -7.78149 -0.43353 C 6.0 -4.89310 -8.55874 0.31080 C 6.0 -5.16776 -8.28274 1.75727 H 1.0 -4.23558 -8.26628 2.32654 H 1.0 -5.79022 -9.08611 2.16452 H 1.0 -5.71925 -7.34591 1.86399 O 8.0 -5.42168 -9.52251 -0.25008 C 6.0 6.07588 5.36035 2.41047 H 1.0 5.41546 6.10513 2.86119 H 1.0 7.08124 5.76404 2.26527 H 1.0 6.13218 4.46273 3.03142 H 1.0 -3.99409 -8.17283 -1.36812 H 1.0 3.86903 -4.58358 -1.46487 H 1.0 8.12201 -4.17578 0.98576 H 1.0 7.65002 -6.10332 -0.54924 H 1.0 6.39871 -2.42357 1.29876 H 1.0 4.43770 3.40075 1.89831 H 1.0 5.53797 6.07004 -2.09755 H 1.0 6.49265 6.60082 0.16210 H 1.0 3.99352 4.14840 -2.34365 H 1.0 -3.36137 2.04034 1.72923 H 1.0 -6.21197 4.48444 -0.10738 H 1.0 -4.92606 4.47294 -2.26256 H 1.0 -2.80635 3.19914 -2.40612 H 1.0 -2.52664 -4.17043 2.04095 H 1.0 -1.10653 -4.71768 -1.99108 H 1.0 -2.49054 -6.72496 -2.19955 H 1.0 -3.89964 -6.14606 1.84813$$END
`

I did this because solvation help stabilize charged species, so perhaps it could converge more easily under solvation, rather than in a vacuum. Under those conditions it didn't get stuck in the first SCF cycle with the default maximum 30 iterations. But I didn't finish this run, as it would probably take far more time.