Re: CCL:gaussian problems
I can answer the first one - as I had the same problem recently.
The ability to use a reduced step size is present in the program,
but the keyword is not properly connected. To use a reduced step size,
use "IOp(1/8=N)", where N has the same meaning as the N in stepsize=N.
Additionally, you should add the option "NoTrustUpdate" to the opt
keyword. So, your input should contain
"#p opt=(Redundant,CalcAll,TIGHT,notrustupdate) iop(1/8=1)"...
Laura Gregerson (Brovold)
9500 Gilman Dr.
La Jolla, CA 92093-0505
On Tue, 9 Jul 2002, Krzysztof Radacki wrote:
> Dear all,
> I have two question and one information concerning gaussian.
> I wanted to perform an optimization with possibly slowest changing
> of geometry. The command line was as:
> #P OPT=(Redundant,CalcAll,StepSize=1,TIGHT) INT=(GRID=99590)
> I got an error:
> QPERR --- A SYNTAX ERROR WAS DETECTED IN THE INPUT LINE.
> #P OPT=(REDUNDANT,CALCALL,STEPSIZE=1,TIG
> What's wrong? On p.129 of User's reference one can find description
> of StepSize in Opt and I can't see why it shouldn't work.
> However calculation of IR was already sometimes discussed on CCL I
> still have uneasy feeling. An example.
> I have a molecule with trigonal bipiramide (D3h) structure. I know
> however that minimum is distorted - both axial ligands are moved out
> of Z-axis in direction of one equatorial ligand (f.e.: ax-ax angle 160)
> and the equatorial are still co-planar (C2v).
> (I hope that you can imagin it from my description).
> Now: If I would distorte D3h structure to C2v with ax-ax angle 175 deg
> and optimized geometry with frozen ax-ax, should IR calculation have
> a one imaginary freq. narrowing ax-ax angle or not? If it gives me no
> Imag - hwat does it mean?
> One can find in books that vibrational analysis should be performed
> only on stationary point - if not it's meaningless. What sense has it
> if one makes such restriction? If I want to be sure that I'm in minimum
> should I repaet all symmetry bounded calculation (like above D3h)
> with NoSymm?
> Last week I wanted to calculated some quite complicated
> molecules like CO or CCH2 and various level of theory.
> Everything was fine with DFT and MP2 but the same inputs
> didn't work for CCSD and CCSD(T).
> The input like:
> #P OPT=(CART,TIGHT) POP=FULL CCSD/6-311G(D,P) Gues=Read
> carbon monoxid
> 0 1
> C 0.000000000000 0.000000000000 0.000000000000
> O 0.000000000000 0.000000000000 1.126962524921
> produced an error:
> Symbolic Z-matrix:
> Charge = 0 Multiplicity = 1
> C 0. 0. 0.
> O 0. 0. 1.12696
> Leave Link 101 at Fri Jul 5 17:23:43 2002, MaxMem= 13107200 cpu:
> (Enter /usr/local/SW/g98/l114.exe)
> NUMERICAL EIGENVECTOR FOLLOWING MINIMUM SEARCH
> INITIALIZATION PASS
> ** ERROR IN INITNF. NUMBER OF VARIABLES ( 0) **
> ** INCORRECT (SHOULD BE BETWEEN 1 AND 50) **
> Error termination via Lnk1e in /usr/local/SW/g98/l114.exe.
> I was supprised that gaussian was looking for z-matrix even if I wrote
> opt=cart. I've repeated the calculation with opt=z-matrix and geometry:
> O 1 r1
> r1 = 1.126962524921
> and gaussian succeed with Normal Termination. So probably I've found small
> Thanks a lot in advance and best reagrds
> Dr. K.Radacki
> Department of Chemistry
> Catalysis and Advanced Materials Section
> Imperial College, London
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