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Alex Granovsky
gran@classic.chem.msu.su

in addition to d5 option, you can try tightening tol1 and tol2 in $mp2grd once again:

 $mp2grd tol1=1d-16 tol2=1d-16 $end

Kind regards,
Alex Granovsky



On Mon Feb 9 '15 7:47pm, Alexander Vasyanin wrote
-------------------------------------------------
>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!