Is Not Changing But Diis Error
this problem in many body files I am getting the error in Gaussian 03 .The error is " The SCF is confused."? The error is Density matrix is not changing but DIIS error= 1.35D-02 CofLast= 3.25D-02. The SCF is confused. Error termination via Lnk1e in C:\G03W\l502.exe at Sat Nov 08 18:21:40 2014. Job cpu time: 0 days 0 hours 43 minutes 7.0 seconds. File lengths (MBytes): RWF= 41 Int= 0 D2E= 0 Chk= 2 Scr= 1 My input file path is %mem=512mb # pbepbe/6-311+g(d) massage scf=(qc,maxcycle=4096)test Please help me how to overcome this thank you. Topics Computational Physics × 384 Questions 44,577 Followers Follow Gaussian (Software) × 768 Questions 305 Followers Follow Nov 12, 2014 Share Facebook Twitter LinkedIn Google+ 0 / 0 All Answers (4) Hamad R. Jappor · University of Babylon this error appear because pbepbe required fitting set in some cases to overcome this error use fitting set SVP or TZVP or QZV or any other fitting set, you can find another fitting sets in guessveiw if you active this option if you chose pbepbe after the basis set windows Nov 13, 2014 Venkatesan Ragavendran · Sri Chandrasekharendra Saraswathi Viswa Mahavidyalaya University HI, I think that your method does not suits your molecule. May be you can try the same with different combination sets. Nov 15, 2014 Ravinder Suresh Konda · The Institute of Science, Mumbai thank you venkatesan Ragavendran sir but all files are with same method but some files are not running Nov 15, 2014 Kapil Dhaka · Technion - Israel Institute of Technology Dear Ravinder, Possible solutions of convergence failure in gaussian 1) SCF=qc will probably solve the problem, albeit at a cost. Change the SCF converger to either SD, Quadratic or Fermi 2) lower the symmetry of optimize
this problem (for a UHF calculation). Using the quadratic SCF (as stated below: scf=qc or scf=xqc) and taking of symmetry by using the NoSymm keyword solved the issue for me. Hope that helps. Antonio De Crisci, Ph.D. Candidate Department of Chemistry University of Toronto > "McGaughey, Georgia B. georgia_mcgaughey*|*merck.com" wrote: > > Sent to CCL by: "McGaughey, Georgia B." [georgia_mcgaughey{}merck.com] > Sarah, > > Have you tried any other key words? For calculating dimer interactions > using MP2/aug-cc-pvdz, I typically use the Counterpoise=3D2 keyword (in > Gaussian) along w/ SCF=3D(qc,tight,maxcycle=3D512). I too had "SCF is > confused" in my output on https://www.researchgate.net/post/Can_any_body_help_me_how_to_overcome_this_problem_in_many_body_files_I_am_getting_the_error_in_Gaussian_03_The_error_is_The_SCF_is_confused occasion prior to adding in the SCF syntax. > > -Georgia=20 > > -----Original Message----- > > From: owner-chemistry!=!ccl.net [mailto:owner-chemistry!=!ccl.net]=20 > Sent: Monday, June 30, 2008 8:39 AM > To: McGaughey, Georgia B. > Subject: CCL:G: SCF is confused? > > > Sent to CCL by: "Sarah R Whittleton" [SWhittleton|dal.ca] > Hi CCL, > > I am trying to run a BSSE single-point calculation (counterpoise) using > http://www.ccl.net/chemistry/resources/messages/2008/07/04.001-dir/ MP2 on an organotin compound. The tin atom is described using the > Stuttgart ECP and an augmented, triple-zeta basis set. After running > for 11 hours the calculation dies uncompleted and the output (copied > below) says that Density matrix is not changing but DIIS error and the > SCF is confused. I have run similar calculations with the same method > on different organotin compounds and this is the only one giving me > trouble. I want to keep the method (MP2) and basis set consistent > between compounds is there anything I can do to make resolve this > problem and allow the calculations to complete normally? I have also > included the first lines of the input file for this calculation. > > I thank you all in advance for any suggestions, > Sarah Whittleton > =09 > ******************************** > Ph.D. Candidate > Department of Chemistry > Dalhousie University > Halifax, NS B3H 4J3 > > > THE END OF THE OUTPUT FILE: > The electronic state of the initial guess is 2-A. > of initial guess=3D 0.7500 > Requested convergence on RMS density matrix=3D1.00D-08 within 128 cycles. > Requested convergence on MAX density matrix=3D1.00D-06
Place Order Request Quote Terms & Conditions Sales Agents More … Home Current Schedule Inquire Register Photos Home Gaussian Contributors Remembering John Pople Honors/Tributes Home Gaussian in Education Other Links of Interest http://www.gaussian.com/g_tech/g_ur/k_scf.htm Home Register Product Sales Agents Mailing List Send Email Address/Phone Info More … SCF https://www.wavefun.com/support/sp_compfaq/converge.html DESCRIPTION This keyword controls the functioning of the SCF procedure. Options are used to specify the desired behavior, alternate algorithms, and so on. The default SCF procedure uses a combination of EDIIS [Kudin02] and CDIIS, with no damping or Fermi broadening. In Gaussian 09, SCF=Tight is the default. The SCF=QC option is often is not helpful with difficult conversion cases. For difficult-to-converge ROHF wavefunctions, where QC cannot be used, add Use=L506 to the route section. See reference [Schlegel91a] for a discussion of SCF convergence and stability. ALGORITHM SELECTION OPTIONS DIIS DIIS calls for and NoDIIS prohibits use of Pulay’s Direct Inversion in the Iterative Subspace (DIIS) extrapolation method [Pulay82]. CDIIS Use only CDIIS. CDIIS implies Damp as well. Fermi Requests temperature broadening during is not changing early iterations [Rabuck99], combined with CDIIS and damping. NoFermi suppresses Fermi broadening and is the default. By default, Fermi also implies Damp and also includes level shifting. Damp Turn on dynamic damping of early SCF iterations. NoDamp is the default. However, damping is enabled if SCF=Fermi or SCF=CDIIS is requested. Note that damping and EDIIS do not work well together. NDamp=N Allow dynamic damping for up to N SCF iterations (the default is 10). QC Calls for the use of a quadratically convergent SCF procedure [Bacskay81]. By default this involves linear searches when far from convergence and Newton-Raphson steps when close (unless the energy goes up). This method is slower than regular SCF with DIIS extrapolation but is more reliable. SCF=QC is not available for restricted open shell (RO) calculations. XQC Add an extra SCF=QC step in case the first-order SCF has not converged. MaxConventionalCycles=N Sets the limit on conventional SCF cycles during SCF=XQC to N. PseudoDiagonalization=N Use pseudo-diagonalization in Link 502 whenever possible, with full diagonalization only at the early cycles, at the end, and every Nth cycle in between. PDiag is a synonym for this option. This is the default for semi-empirical methods (the default is N=30). FullD
covers the typical areas to examine when a calculation has trouble converging. The first question to ask is "Am I having problems converging the geometry, or the wavefunction?" The answer to this question will lead to different sections of this FAQ below. The first section "General Issues" covers some topics which are relevant to both geometry and wavefunction (SCF) convergence. General Issues Geometry Optimization Issues Special Issues with Transition State Searches Wavefunction (SCF) Convergence Issues Converging the CPHF in frequency/IR calculation (the "iterz" error) Concluding Remarks Some Common Questions I ran a geometry optimization followed by a frequency calculation and it showed a negative eigenvalue. Doesn't this mean I've found a transition state and not a minima? A geometry optimization ran out of cycles, how do I restart it? What are the specifics of the CONVERGE keyword? I got a 'CnV slipped through' error message. What should I do? Keyword List General Issues Some common convergence issues: The geometry is poor, The charge is wrong, The multiplicity is wrong. Symmetry is causing a problem. Geometry Examine the molecule carefully. Try the same calculation at a simpler theory level or with a smaller basis set. If the lower theories work, they are likely good starting points for advanced theories. (For quantum chemical calculations, theoretical approaches are listed in order of increasing complexity: Semi Empirical < Hartree-Fock < Density Functional < Configuration Interaction and Moller Plesset < Advanced Correlated). Examine the molecule's current geometry carefully; do the bond distances and angles seem correct? (Or nearly correct?) Molecular Mechanics can sometimes produce strange results when metals are involved. Semi-empirical is fast and often very good, but it also may also suffer from poor approximations, and may not be good enough for your molecule. Another common problem is that the current geometry may have a symmetry that is not a reasonable energy minima in the theory you are attempting to use. Turning "Symmetry" off is sometimes appropriate; this can be done by using the IGNORESYMMETRY keyword. Sometimes it is also necessary to physically break symmetry by slightly changing bond distances or angles. (Watch the symmetry label in the bottom right of the screen to determine if your changes are large enough.) Charge Make sure to count electrons and look for radicals in your molecule. The charge and number of unpaired electrons specified in the CalculationDialogue must be consistent with the molecule. Unpaired Electrons Are there unpaired electrons? If so, you may want to choose an unrestricted calculation