Molcas Forum

lijingbai2009

Member

Registered: 2019-08-28

Posts: 29

Error in Saddle method for TS optimization

Hi,

I have read other posts about how to use the "saddle" method. I have prepared two xyz files for my reactant and product.

reac.xyz:

 16
-307.34418311
C        0.806637710     -0.782874530     -1.645349790
C        0.767832890	  0.761874990     -1.533349060
C	-0.759406050     -0.750907460     -1.545702580
C        0.640292690	  0.986665810     -0.021202650
C	-0.797521120	  0.794856730     -1.643020150
C	-0.809861940	  1.155527890     -0.143864090
H	-1.357309650	  1.319234610     -2.408888560
H        1.371496060     -1.299842310     -2.412537550
H        1.419957720	  1.455576410     -2.072344000
H	-1.407946090     -1.439353370     -2.095670170
H        1.305632780	  1.211309540	   0.734447980
H	-1.538765380	  1.678926850	   0.492571950
C        0.809129270     -1.157951730     -0.149684430
H        1.533657440     -1.687942660	   0.486307050
C	-0.641820780     -0.990316430     -0.035007120
H	-1.312128570     -1.222140870	   0.714057130

prod.xyz:

16
-307.31849119
C        0.807346440     -0.777615650     -1.649998270
C        0.772581060      0.762927770     -1.540091500
C       -0.764111110     -0.751897220     -1.552487660
C        0.679769240      0.944685570     -0.012625440
C       -0.798199410      0.789641710     -1.647725430
C       -0.834541670      1.123690140     -0.135922070
H       -1.357297720      1.319416880     -2.409297000
H        1.371486760     -1.300020470     -2.412947840
H        1.420203290      1.456166940     -2.073789590
H       -1.408182410     -1.439929700     -2.097123790
H        1.306476660      1.218286660      0.731882330
H       -1.537805270      1.681139140      0.491662840
C        0.833752330     -1.126185340     -0.141270880
H        1.532702770     -1.690146530      0.485369130
C       -0.681348630     -0.948425700     -0.026290580
H       -1.312955350     -1.229090740      0.711419720

My input file is:

&GATEWAY
 coord=reac.xyz
 RP-coordinates
 reac.xyz
 prod.xyz
 basis
 cc-pvdz
 Group=c1
 RICD

>> Do while

&SEWARD
doanalytic

&RASSCF
 fileorb=$MOLCAS_PROJECT.StrOrb
 Spin=1
 Nactel=4 0 0 
 Inactive=26
 Ras1=0
 Ras2=4
 Ras3=0
 ITERATIONS=200,100
 CIRoot=2 2 1
 Rlxroot=1

&SLAPAF
maxstep=0.1
Iterations=200
thrshld=0.0 5.0D-4

>> End Do

However, this job immediately returned an error message:

 **************************
 * Enable TS optimization *
 **************************

 -- TS optimization a la the Saddle approach
   Last Macro iteration
 ###############################################################################
 ###############################################################################
 ###                                                                         ###
 ###                                                                         ###
 ###    Location: gxRdRun                                                    ###
 ###    Unit    :                     0                                      ###
 ###    File    : stderr                                                     ###
 ###    RunFile does not exist                                               ###
 ###                                                                         ###
 ###                                                                         ###
 ###############################################################################
 ###############################################################################

Can anyone help me solve the problem? Thanks!

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,085

Re: Error in Saddle method for TS optimization

I think your reactant and product are too close in geometry and their "distance" is less than the default step size. Try adding "SaddleStep = 0.01" to &GATEWAY, or probably less.