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Siddheshwar Chopra

sidhusai@gmail.com

Dear Alex,

Thats not exactly the answer for what I asked. I want to know what should be the values of FREQ(1) for frequencies corresponding to 1MHz to 20GHz. As I understood from the FIREFLY manual, I can only set a minimum of 0.000001 a.u. which corresponds to around 10e11 Hz. Thats the concern to me.. This range means that I can set a minimum of 100Ghz or so.. Please help.

Regards,

n Sat Jun 22 '13 6:09am, Alex Granovsky wrote

----------------------------------------------

>Dear Siddheshwar,

>you can specify up to 10 frequencies at once.

>Set nfreq to 10 and provide desired values

>in the freq array. It is recommended to set the

>first frequency to zero and enlist frequencies

>in ascending order. Note they are given in atomic

>units so you need to convert your MHz or GHz values

>to atomic units.

>Hope this helps.

>Kind regards,

>Alex

>On Wed Jun 19 '13 2:24pm, Siddheshwar Chopra wrote

>--------------------------------------------------

>>Dear Alex,

>>Thank you for the information. As per your input file, I ran the program to find polarizability of a molecule. I wish to ask that is it possible to give the FREQ(n) array for a range of 1MHz to 20GHz? Is it possible to get this frequency range in FIREFLY?

>>Regards,

>>On Tue Jun 18 '13 8:02pm, Alex Granovsky wrote

>>----------------------------------------------

>>>Dear Siddheshwar,

>>>dielectric constant is a macroscopic property.

>>>At microscopic level, we can compute frequency-dependent

>>>polarizabilities and hyper-polarizabilities. Having a certain

>>>model of the macroscopic body one can relate a microscopic

>>>properties such as polarizability to a dielectric constant.

>>>Below please find a sample file with computation of

>>>frequency-dependent polarizability for benzene molecule

>>>using PBE0 density functional. In brief, this is done

>>>using runtyp=TDHF and specifying some DFTTYP.

>>>If no DFTTYP is given, then these are indeed classical

>>>TDHF calculations, if DFTTYP is given then they in fact

>>>become TDDFT computations.

>>>

$CONTRL SCFTYP=RHF DFTTYP=PBE0 runtyp=TDHF nosym=1 $END $SYSTEM TIMLIM=300 MEMORY=3000000 $END $BASIS GBASIS=N31 NGAUSS=6 NDFUNC=1 NPFUNC=1 $END $TDHF NFREQ=2 FREQ(1)=0,0.1 $END $DATA C6H6 Dnh 6 CARBON 6.0 -0.698164472 1.209256337 0.000000000 HYDROGEN 1.0 -1.241338149 2.150060743 0.000000000 $END

>>>

>>>

>>>Kind regards,

>>>Alex Granovsky

>>>

>>>

>>>

>>>

>>>

>>>

>>>

>>>On Fri Jun 14 '13 11:00am, Siddheshwar Chopra wrote

>>>---------------------------------------------------

>>>>Dear Sir,

>>>>I would be glad if you could throw some light on How to calculate the frequency dependent Dielectric constant using FIREFLY?? As far as I have read, DFPT is used to do the same... please help.

>>>>Regards,

Sat Jun 22 '13 10:27am

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