# I'm a layman, but I'd like to know to to use GAMESS for some specific tasks

I have Avogadro and GAMESS. I modeled the sulfuric acid molecule using Avogadro, then I asked it to generate an input for GAMMES to calculate the transitional state (I'm hoping this will get me somehow closer to my computational modeling of real chemistry). But GAMESS says the job finished with an error, and I don't know why.

It's worth noticing Avogadro seems to spell one of the commands wrong, and I have to manually correct it. Avogadro issues the command \$STATTP but GAMESS does not recognize this command, so I change it to \$STSTEP, and it ends with an error, and I try the other keyword possible \$STPT and I also get an error. Here's my 2 inputs and outputs: http://pastebin.com/TabWC9wr This is what happens when I do what you told me, @Mitradip Das: ## INPUT ! File created by the GAMESS Input Deck Generator Plugin for Avogadro$BASIS GBASIS=STO NGAUSS=3 $END$CONTRL SCFTYP=RHF RUNTYP=SADPOINT $END$STATPT OPTTOL=0,0001 NSTEP=20 $END$DATA
Title
C1
S    16.0    -3.61564     3.32108     0.04978
O     8.0    -4.51377     4.03518    -0.82228
O     8.0    -2.75016     3.96121     1.00661
O     8.0    -2.67033     2.39549    -0.85711
O     8.0    -4.49699     2.21900     0.81326
H     1.0    -5.20320     1.93219     0.19859
H     1.0    -1.81232     2.32072    -0.38885
$END  ## OUTPUT (showing only the error part, full output can be viewed here (http://pastebin.com/HRh1fS4d)  CONSTANT LIST TOO LONG **** ERROR READING INPUT GROUP$STATPT   *****
THE PROBLEM IS WITH THIS INPUT LINE, NEAR THE X MARKER
$STATPT OPTTOL=0,0001 NSTEP=20$END
X
THE ONLY KEYWORDS ACCEPTED IN THIS GROUP ARE:
METHOD    UPHESS    NSTEP     NNEG      IFOLOW    DXMAX
RMIN      RMAX      RLIM      RESTAR    HESS      OPTTOL
IHREP     HSSEND    IFREEZ    NPRT      NPUN      PURIFY
ITBMAT    MOVIE     TRUPD     TRMAX     TRMIN     STPT
STSTEP    PROJCT    IFCART    NPRTHS    KDIAGH    IACTAT
IHMCON    FHMCON    SHMCON
TROUBLE INTERPRETING $STATPT OBTAINING INITIAL HESSIAN, HESS=READ ***** ERROR, YOU DID NOT SUPPLY A$HESS GROUP.
EXECUTION OF GAMESS TERMINATED -ABNORMALLY- AT Wed Jul 27 12:23:49 2016
580000  WORDS OF DYNAMIC MEMORY USED
STEP CPU TIME =     0.00 TOTAL CPU TIME =        0.0 (    0.0 MIN)
TOTAL WALL CLOCK TIME=        0.0 SECONDS, CPU UTILIZATION IS 100.01%

job aborted:

• In general, this is not the right place to ask these questions since they are entirely about the software you use. You should also try to work through at least the first few examples in the manual. Starting to learn a program with a saddle point optimisation is a very bad choice, since they really need some understanding of the program first. The error you get is problematic because it points you to the wrong position. Try opttol=0.001. You might also need to tell the program how to obtain the hessian. Jul 27 '16 at 15:45
• If the input geometry is not close to a transition state (which one? what do you want to find?), you might not get any conversion. Try running a single point calculation first. Don't rely on the avogadro input generator, it makes mistakes. Understand the keywords you are using and structure your input file accordingly. Leave comments in your input explaining what you are actually trying to achieve. Gamess is difficult to learn and even if your calculation runs without error, you might not get any meaningful results. Jul 27 '16 at 15:50
• I see. It is not a very intuitive program to use. even the command line to invoke it is verbose. Jul 27 '16 at 16:19
• You're asking it to do a transition state calculation (RUNTYP=SADPOINT ) which doesn't make sense. A transition state occurs between two different structures, such as between reactants and product or when ammonia goes through its umbrella. Try an equilibrium run with RUNTYP=OPTIMIZE instead. This should get you going. If you are having difficulty I will generate an input file for you. It is well worth persevering. Oct 31 '17 at 12:05

For GAMESS, the command is not $\$STATTP$, but it is$\$STATPT$. Also, please change the commas to dot, otherwise it considers it to be a part of the number.