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Re: How to get rid of Imaginary Frequencies.....

Thomas
thomaspijper@hotmail.com


Dear Siddheshwar,

Could you please post the complete output of your Hessian calculation? This would allows us to see what kind of imaginary frequencies you're finding.


Kind regards,
Thom



On Wed Feb 6 '13 10:56am, Siddheshwar Chopra wrote
--------------------------------------------------
>Dear Sir,
>This in regard to my problems with getting rid of imaginary frequencies in the vibrational data. I have tried changing the basis sets, changed the ITOL, ICUT values... Please suggest me what should I do to ge trid of imaginary frequencies?? Currently I am trying out PC-2 basis set. A sample input commands are as follows:

> INPUT CARD> $SYSTEM MEMORY=12065831 aoints=dist TIMLIM=525600 KDIAG=1 $END                
> INPUT CARD> $CONTRL INTTYP=HONDO ICUT=11 ITOL=30 RUNTYP=HESSIAN SCFTYP=RHF $END            
> INPUT CARD> $CONTRL DFTTYP=B3LYP COORD=UNIQUE NZVAR=132 $END                              
> INPUT CARD> $CONTRL MAXIT=10000 MOLPLT=.t. PLTORB=.t. $END                                
> INPUT CARD>! $CONTRL EXETYP=CHECK $END                                                    
> INPUT CARD> $BASIS GBASIS=N31 NGAUSS=6 NDFUNC=1 NPFUNC=1 $END                              
> INPUT CARD> $STATPT opttol=10E-7 NSTEP=200 Method=GDIIS HSSEND=.TRUE. $END                
> INPUT CARD> $SMP HTTFIX=.f. $END                                                          
> INPUT CARD> $p2p p2p=.t. mxbuf=2048 dlb=.t. $END                                          
> INPUT CARD> $SCF dirscf=.t. fdiff= .f. diis=.t. $END                                      
> INPUT CARD> $DFT HFX(1)=0.15 $END                                                          
> INPUT CARD> $ZMAT DLC=.t. AUTO=.t. $END                                                    
> INPUT CARD> $FORCE NVIB=2 $END                          

>Please help me.
>
>
>Regards,
>


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