## Firefly and PC GAMESS-related discussion club

Learn how to ask questions correctly

** KBr molecule - B3LYP1 optimization failed (SCF not converged) **
Marko Mitic

marko.mitic@ffh.bg.ac.rs

Dear All,I'm new to Firefly. I'm trying to do optimization and frequency analysis of KBr molecule at level of B3LYP1 with Stuttgart ECP basis and their corresponding valence basis set. Diatomic KBr is just a start, we have in plan to study potassium bromide clusters.

First, I have done RHF calculation (opt,freq) and everything is working great. I used MOs from RHF calculation for the second calculation, DFT one. The problem is that DFT optimization giving me an error, i.e. SCF not converged. Here is part of my input (I'm attaching the rest):

!KBr molecule DFT opt and freq

$CONTRL

SCFTYP=RHF RUNTYP=OPTIMIZE DFTTYP=B3LYP1 MULT=1 ICHARG=0 COORD=ZMT UNITS=ANGS ECP=read

$END

$CONTRL EXETYP=RUN INTTYP=HONDO ICUT=11 ITOL=30 D5=.T. NZVAR=1 MAXIT=100 $END

$SYSTEM TIMLIM=300 MEMORY=30000000 $END

$BASIS EXTFIL=.T. GBASIS=BAZA $END

$GUESS GUESS=MOREAD NORB=27 $END

$SCF DIRSCF=.T. $END

$STATPT HSSEND=.T. NPRT=-2 NSTEP=200 $END

$FORCE NVIB=2 VIBSIZ=0.005 $END

$DATA

potassium bromide, B3LYP1/9-ve PP(K),cc-pvtz-PP(Br)

CNV 4

K

BR 1 rKBr

rKBr=2.83

$END

The error I get at the end is:

***** FAILURE TO LOCATE STATIONARY POINT, SCF HAS NOT CONVERGED

UPDATED HESSIAN, GEOMETRY, AND VECTORS WILL BE PUNCHED FOR RESTART

I tried to change NORB, NSTEP, MAXIT, but didn't get any results. Also, I have tried with different functional (B3P86), but nothing.

I have outputs from Gaussian 09 for this molecule, my friend do that for me. RHF from Firefly are the same as results from G09, DFT opt freq in G09 works fine.

Please, if anyone can help me to solve this problem. Thanks in advance.

I'm attaching files from RHF and DFT calculation.

Best regards,

Marko

| This message contains the 236 kb attachment
[ **KBr molecule, RHF and DFT.zip** ] KBr molecule, RHF and DFT, input and output files |

Sun Dec 4 '16 3:59pm

This message read **505** times