[molpro-user] puzzle about the reaction path following options

[MHT]

Hi,

I did a reaction path calculation/IRC with idir=1, which means the first 
optimization step will be along the transition vector from TS.
Normally, it will go to "an asymptote".
But sometimes this asymptote is not so "smooth", there are one or two or 
more points which are a little higher than this asymptote. 
Although, this job could be normally terminated, it is quite strange. How 
can the energy of these strange points go higher than asymptote.
See the following output:

 END OF GEOMETRY OPTIMIZATION.    TOTAL CPU:      3942.9 SEC
                                                                                                                               
 ITER.   ENERGY(OLD)    ENERGY(NEW)      DE          GRADMAX     GRADNORM    
GRADRMS     STEPMAX     STEPLEN     STEPRMS
   1  -152.90707395  -152.90707561    -0.00000165  0.00000117  0.00000143  
0.00000010  0.01158242  1.00000000  0.06666667
   2  -152.90707561  -152.90713573    -0.00006013  0.00010077  0.00018109  
0.00001207  0.07969603  0.13160862  0.00877391
   3  -152.90713573  -152.90721859    -0.00008286  0.00226480  0.00269265  
0.00017951  0.04601674  0.07766024  0.00517735
   4  -152.90721859  -152.90729683    -0.00007823  0.00073856  0.00127870  
0.00008525  0.04450214  0.07562299  0.00504153
   5  -152.90729683  -152.90738954    -0.00009272  0.00158575  0.00221004  
0.00014734  0.04626073  0.07690365  0.00512691
   6  -152.90738954  -152.90748236    -0.00009282  0.00162790  0.00214846  
0.00014323  0.04388172  0.07636533  0.00509102
   7  -152.90748236  -152.90758151    -0.00009915  0.00190875  0.00260383  
0.00017359  0.04739069  0.07687329  0.00512489
   8  -152.90758151  -152.90767629    -0.00009478  0.00183900  0.00242181  
0.00016145  0.04508402  0.07641860  0.00509457
   9  -152.90767629  -152.90777065    -0.00009435  0.00183494  0.00252928  
0.00016862  0.04810958  0.07647086  0.00509806
  10  -152.90777065  -152.90785786    -0.00008722  0.00145822  0.00204495  
0.00013633  0.04665480  0.07566115  0.00504408
  11  -152.90785786  -152.90793198    -0.00007412  0.00066289  0.00106386  
0.00007092  0.04768685  0.07596757  0.00506450
  12  -152.90793198  -152.90799646    -0.00006448  0.00055258  0.00089460  
0.00005964  0.05031503  0.08149318  0.00543288
  13  -152.90799646  -152.90803970    -0.00004324  0.00042039  0.00068701  
0.00004580  0.04668051  0.07634139  0.00508943
  14  -152.90803970  -152.90806354    -0.00002384  0.00026877  0.00045157  
0.00003010  0.04571338  0.07621047  0.00508070
  15  -152.90806354  -152.90806761    -0.00000406  0.00010776  0.00019717  
0.00001314  0.02897178  0.04941772  0.00329451
  16  -152.90806761  -152.90806766    -0.00000005  0.00004433  0.00006608  
0.00000441  0.00248125  0.00380770  0.00025385
  17  -152.90806766  -152.90806766     0.00000000  0.00000817  0.00001507  
0.00000100  0.00013310  0.00020669  0.00001378
  18  -152.90806766  -152.90806766     0.00000000  0.00000240  0.00000329  
0.00000022  0.00009225  0.00014318  0.00000955
  19  -152.90806766  -152.90806766     0.00000000  0.00000026  0.00000055  
0.00000004  0.00000895  0.00000925  0.00000062
  20  -152.90806766  -152.90790849     0.00015917  0.00000040  0.00000054  
0.00000004  0.13188970  0.19228404  0.01281894
  21  -152.90790849  -152.90806766    -0.00015917  0.00522778  0.00692745  
0.00046183  0.13189403  0.19229438  0.01281963
  22  -152.90806766  -152.90806766     0.00000000  0.00000014  0.00000020  
0.00000001  0.00000188  0.00000288  0.00000019
  23  -152.90806766  -152.90758378     0.00048388  0.00000036  0.00000045  
0.00000003  0.11612722  0.16830718  0.01122048
  24  -152.90758378  -152.90806766    -0.00048388  0.01702191  0.01971109  
0.00131407  0.11612209  0.16830180  0.01122012
  25  -152.90806766  -152.90806766     0.00000000  0.00000006  0.00000011  
0.00000001  0.00000449  0.00000483  0.00000032


yours sincerely
MHT