Alex Granovsky
gran@classic.chem.msu.su
sorry for delayed reply.
I'd suggest you the following modifications of your original input:
1. 6-31G* is not spherical basis set. Set D5 option to .false.
2. Use $MP2 cutoff=1d-20 $END
3. Use $TRANS cuttrf=1.0d-20 $END
4. Relax acurcy in MCSCF to 1.0d-8 or maybe even to 3.0d-8.
acurcy=1d-9 is too tight and often cannot be reached due to finite
precision of floating point operations, so no convergence in MCSCF.
Hope this helps.
Kind regards,
Alex Granovsky
On Fri Jan 6 '17 11:56am, Dawid wrote
-------------------------------------
>Dear All,
>I would like to do XMC-QDPT2 geometry optimization of the ground-state
>using single-state CASSCF reference.
>The issue I am encountering is that the MCSCF calculations (in course
>of the geometry optimization) do not converge when high precision is
>enforced even though the output looks like this:
> ITER TOTAL ENERGY DEL(E) LAG.ASYMM. SQCDF MICIT DAMP
> ----------START APPROXIMATE SECOND ORDER MCSCF----------
> 1 -439.972125989 -439.972125989 0.000560 2.088E-06 1 0.0000
> 2 -439.972130903 -0.000004914 0.000203 1.353E-06 1 0.0000
> 3 -439.972131634 -0.000000731 0.000060 3.849E-07 1 0.0000
> 4 -439.972131722 -0.000000088 0.000021 3.551E-07 1 0.0000
> 5 -439.972131755 -0.000000032 0.000009 4.861E-08 1 0.0000
> 6 -439.972131760 -0.000000005 0.000008 4.466E-08 1 0.0000
> 7 -439.972131763 -0.000000003 0.000004 1.206E-08 1 0.0000
> 8 -439.972131764 -0.000000001 0.000002 5.590E-09 1 0.0000
> 9 -439.972131764 0.000000000 0.000001 7.682E-10 1 0.0000
> 10 -439.972131764 0.000000000 0.000001 1.915E-10 1 0.0000
> 11 -439.972131764 0.000000000 0.000000 7.585E-11 1 0.0000
>.
>.
>.
> 95 -439.972131764 0.000000000 0.000000 1.789E-18 1 0.0000
> 96 -439.972131764 0.000000000 0.000000 3.993E-18 1 0.0000
> 97 -439.972131764 0.000000000 0.000000 1.440E-18 1 0.0000
> 98 -439.972131764 0.000000000 0.000000 6.709E-19 1 0.0000
> 99 -439.972131764 0.000000000 0.000000 5.794E-11 1 0.0000
> 100 -439.972131764 0.000000000 0.000011 5.792E-11 1 0.0000
> EXCESSIVE NUMBER OF ITERATIONS...
>Nevertheless couple of geometry searches are performed until
>.
>.
>.
> 82 -439.920263839 0.002669544 0.161276 5.195E-01 1 0.0000
> SOSCF IS SCALING ROTATION ANGLE MATRIX, SQCDF= 84.966198
> SOSCF IS SCALING ROTATION ANGLE MATRIX, DXMAX= 2.229427
> 83 -439.917588524 0.002675315 0.169614 5.195E-01 1 0.0000
> SOSCF IS SCALING ROTATION ANGLE MATRIX, SQCDF= 3.359397
> SOSCF IS SCALING ROTATION ANGLE MATRIX, DXMAX= 2.229428
> 84 -439.914768467 0.002820057 0.174227 5.195E-01 1 0.0000
> SOSCF ENCOUNTERS A SERIOUS PROBLEM IN -SONEWT-
> THE ROTATION ANGLE VECTOR HAS A HUGE NORM, SQCDF= 7.058E+03
> REEXAMINE STARTING VECTORS, APPROPRIATENESS OF YOUR SCFTYP, ETC...
>
>
>On the other hand, if I use default convergence criteria:
> ITER TOTAL ENERGY DEL(E) LAG.ASYMM. SQCDF MICIT DAMP
> ----------START APPROXIMATE SECOND ORDER MCSCF----------
> 1 -439.971787958 -439.971787958 0.000714 5.267E-06 1 0.0000
> 2 -439.971803845 -0.000015887 0.000195 1.130E-06 1 0.0000
> 3 -439.971805101 -0.000001256 0.000103 1.072E-07 1 0.0000
> 4 -439.971805179 -0.000000078 0.000037 4.774E-08 1 0.0000
> 5 -439.971805197 -0.000000018 0.000013 8.471E-09 1 0.0000
> 6 -439.971805199 -0.000000002 0.000003 8.942E-10 1 0.0000
>the MCSCF calculations converge correctly.
>The active space is fine through the calculations (its size and
>orbitals that create it).
>So what is the possible reason for that issue? I attach input
>file for calculations that do not converge correctly.
>