Thomas Pijper
thomaspijper@hotmail.com
With the aug-cc-pVDZ basis one should enable spherical functions. These are enabled with
$CONTRL D5=.T. $END
See pages 68-69 of the manual for more details. Enabling spherical functions may reduce partial linear dependence in your basis and help in getting more accurate MP2 gradients.
Hope this helps.
Kind regards,
Thom
On Mon Feb 9 '15 7:47pm, Alexander Vasyanin wrote
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>Dear All,
>I've got a problem with geometry optimization (see attached input file). DFT methods (B3LYP, PBE0) with the same input geometry converge fine, but MP2 fails to converge showing a progress like this:
>$ grep 'E=' 1.dat | cat -n
> 1 E= -727.7926962177 GMAX= 0.0001417 GRMS= 0.0000243
> 2 E= -727.7926962929 GMAX= 0.0001120 GRMS= 0.0000170
> 3 E= -727.7926963478 GMAX= 0.0001410 GRMS= 0.0000230
> 4 E= -727.7926963300 GMAX= 0.0001064 GRMS= 0.0000191
> 5 E= -727.7926963359 GMAX= 0.0000947 GRMS= 0.0000164
> 6 E= -727.7926963183 GMAX= 0.0000374 GRMS= 0.0000059
> 7 E= -727.7926963183 GMAX= 0.0000374 GRMS= 0.0000059
> 8 E= -727.7926963427 GMAX= 0.0000564 GRMS= 0.0000109
> 9 E= -727.7926821007 GMAX= 0.0022164 GRMS= 0.0003298
> 10 E= -727.7926963076 GMAX= 0.0001419 GRMS= 0.0000216
> 11 E= -727.7926963186 GMAX= 0.0000727 GRMS= 0.0000111
> 12 E= -727.7926963017 GMAX= 0.0001004 GRMS= 0.0000204
> 13 E= -727.7926963017 GMAX= 0.0001004 GRMS= 0.0000204
> 14 E= -727.7926963256 GMAX= 0.0000705 GRMS= 0.0000113
> 15 E= -727.7926963045 GMAX= 0.0001233 GRMS= 0.0000208
> 16 E= -727.7926963005 GMAX= 0.0000897 GRMS= 0.0000190
> 17 E= -727.7926963306 GMAX= 0.0001289 GRMS= 0.0000226
> 18 E= -727.7926963143 GMAX= 0.0000295 GRMS= 0.0000066
> 19 E= -727.7926963143 GMAX= 0.0000295 GRMS= 0.0000066
> 20 E= -727.7926963311 GMAX= 0.0000623 GRMS= 0.0000102
> 21 E= -727.7926960335 GMAX= 0.0002230 GRMS= 0.0000479
> 22 E= -727.7926963305 GMAX= 0.0000966 GRMS= 0.0000163
> 23 E= -727.7926963281 GMAX= 0.0000657 GRMS= 0.0000119
> 24 E= -727.7926963216 GMAX= 0.0001480 GRMS= 0.0000286
> 25 E= -727.7926963216 GMAX= 0.0001480 GRMS= 0.0000286
> 26 E= -727.7926963217 GMAX= 0.0000691 GRMS= 0.0000123
> 27 E= -727.7926963181 GMAX= 0.0000618 GRMS= 0.0000099
> 28 E= -727.7926961166 GMAX= 0.0001413 GRMS= 0.0000266
> 29 E= -727.7926962196 GMAX= 0.0000940 GRMS= 0.0000245
> 30 E= -727.7926963158 GMAX= 0.0000997 GRMS= 0.0000160
> 31 E= -727.7926963158 GMAX= 0.0000997 GRMS= 0.0000160
> 32 E= -727.7926963209 GMAX= 0.0001290 GRMS= 0.0000192
> 33 E= -727.7926963169 GMAX= 0.0000520 GRMS= 0.0000103
> 34 E= -727.7926963562 GMAX= 0.0001067 GRMS= 0.0000186
> 35 E= -727.7926963414 GMAX= 0.0000815 GRMS= 0.0000132
>I've tried to use symmetry (CS) to make calculation faster with IHREP=5 option, but it also didn't help to reach convergence even after 40 iterations.
>Is it possible to improve convergence (may be with some option in $MP2GRD)?
>Thanks in advance!