Firefly and PC GAMESS-related discussion club

Learn how to ask questions correctly  
We are NATO-free zone

Re: How do I get a better initial guess (SnI3)?

Alex Granovsky


First, you need to add $contrl d5=.t. $end option to your input file.
Second, you need to use either $contrl inttyp=hondo $end or direct scf
with fastints code ($scf dirscf=.t. $end, $contrl fstint=.t. $end ).

Hope this helps.

Kind regards,
Alex Granovsky

On Wed Jan 24 '18 11:37pm, David Shobe wrote
>How can I improve on GUESS=HUCKEL when it fails to perform?

>At least I'm assuming the initial guess is at fault and not the choice of parameters EXTRAP DAMP SHIFT DIIS and SOSCF. This is because from beginning to end of the DFT orbital calculation, I am getting wildly different energies from one iteration to the next.

>I tried SnI3+ (which is a closed shell), but got the same result. So my question is: now what?

>I could try to swap occupied and unoccupied orbitals with NORDER, but I'm flying blind.

>If you're wondering: Yes, I do have diffuse functions. SnI3 converges fine when you omit them.  But I think I need the diffuse functions for accuracy.

>Regards, and thanks for any help,
>--David Shobe

[ Previous ] [ Next ] [ Index ]           Thu Jan 25 '18 9:42am
[ Reply ] [ Edit ] [ Delete ]           This message read 429 times