Converge problem in the optimization on G94
Dear Netters;
I use the gaussian 92 and g94 programs. I have a problem about the geometry
optimization
and frequency analysis.
After the geometry optimization completed ,I
performed the frequency calculation analysis. However, from the output of
frequency
analysis ,
sometimes Optimization is not completed because values about displacement
exceed the thresholds. How should I resolved it and wolud you tell me your
thought about this problem ?
I show the following example, for the same structure,
---
from the optimization--
-------------------------------------------------------------------
Center Atomic Forces (Hartrees/Bohr)
Number Number X Y Z
-------------------------------------------------------------------
1 8 -.000000354 .000000167 -.000003124
2 6 .000000252 -.000001602 -.000002878
3 1 .000000565 .000001205 .000000257
4 6 -.000000992 -.000003086 .000002942
5 3 .000000015 -.000001105 .000001460
6 1 -.000000899 -.000000567 -.000001878
7 1 .000001063 .000000184 .000000899
8 1 -.000001582 .000000683 -.000000353
9 6 .000003439 .000004875 .000000566
10 1 -.000003443 -.000001508 .000000881
11 1 .000002364 .000002099 .000001358
12 8 -.000000689 -.000001094 .000002595
13 6 .000000214 .000000425 -.000003147
14 1 .000000368 .000000556 .000000653
15 1 -.000000386 .000000051 .000001280
16 1 .000001086 -.000000075 .000000193
17 3 -.000005487 -.000001164 .000001193
18 6 .000006121 -.000009568 -.000012355
19 1 .000003418 .000007083 .000002534
20 1 -.000008932 -.000002296 -.000001040
21 1 .000003860 .000004737 .000007963
-------------------------------------------------------------------
Cartesian Forces: Max .000012355 RMS .000003356
Internal Forces: Max .000008263 RMS .000002536
Item Value Threshold Converged?
Maximum Force .000008 .000450 YES
RMS Force .000003 .000300 YES
Maximum Displacement .001537 .001800 YES
RMS Displacement .000439 .001200 YES
from the frequency analysis---
-------------------------------------------------------------------
Center Atomic Forces (Hartrees/Bohr)
Number Number X Y Z
-------------------------------------------------------------------
1 8 -.000000351 .000000168 -.000003123
2 6 .000000251 -.000001603 -.000002879
3 1 .000000564 .000001202 .000000257
4 6 -.000000992 -.000003084 .000002944
5 3 .000000015 -.000001106 .000001461
6 1 -.000000899 -.000000567 -.000001879
7 1 .000001062 .000000184 .000000899
8 1 -.000001581 .000000682 -.000000354
9 6 .000003440 .000004876 .000000569
10 1 -.000003443 -.000001508 .000000881
11 1 .000002365 .000002099 .000001359
12 8 -.000000691 -.000001095 .000002592
13 6 .000000211 .000000432 -.000003151
14 1 .000000365 .000000554 .000000654
15 1 -.000000385 .000000052 .000001284
16 1 .000001089 -.000000078 .000000192
17 3 -.000005487 -.000001164 .000001193
18 6 .000006119 -.000009568 -.000012354
19 1 .000003418 .000007083 .000002533
20 1 -.000008932 -.000002296 -.000001040
21 1 .000003861 .000004737 .000007963
-------------------------------------------------------------------
Cartesian Forces: Max .000012354 RMS .000003356
Internal Forces: Max .000008262 RMS .000002536
Item Value Threshold Converged?
Maximum Force .000008 .000450 YES
RMS Force .000003 .000300 YES
Maximum Displacement .001946 .001800 NO
RMS Displacement .000524 .001200 YES
----
Sincerely,
Seiji Mori
Department of Chemistry
The University of TOkyo
email:smori - at - chem.s.u-tokyo.ac.jp