## Firefly and PC GAMESS-related discussion club

Learn how to ask questions correctly

** Re^6: density convergence **
Siddheshwar Chopra

sidhusai@gmail.com

Dear Alex,

Will adding "$dft lmax=47 nrad=127 $end" to the input file INCREASE the computation time? If yes then by how much? I am facing the convergence problem too, but am worried about the computation time. Please help. Earlier I had used nrad=99.

On Wed Jan 1 '14 7:46pm, Alex Granovsky wrote

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

>Dear David,>As to DFT grids, try to set

>

$dft lmax=47 nrad=127 $end

>Kind regards,

>Alex Granovsky

>

>

>

>On Wed Jan 1 '14 4:23pm, David G. wrote

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

>>>Dear Pavel

>>yes actually I am using diffuse functions and I should have dropped off some of them to reach equilibrium. After then I should use diffuse functions to compute the properties of the system accurately. Could I increase the DFT grid accuracy using just LAMX ?

>>

>>

>>Dear Slawomir

>>adding the following line didn't help to make density convergence better than before.

>>$CONTRL INTTYP=HONDO ICUT=15 ITOL=35 LEXCUT=5 $END

>>

>>

>>Many Thanks for your kind attentions and comments.

>>Sincerely David

>>

>>

>>

>>On Wed Jan 1 '14 9:50am, Pavlo Solntsev wrote

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

>>>Dear David.

>>>My two cents.

>>>Do you use diffuse functions? Is geometry really good? In the first case you may drop off some diffuse functions to achieve a convergence. If geometry is not good, you may try to use smaller basis set and then expend it up to desired size. Keep in mind, for DFT you may also need to increase grid accuracy, especially for transition metals.

>>>Pavel.

>>

Mon Jan 20 '14 10:27am

This message read **680** times