Dear Molpro users,<br><br>Does anybody know how to restart an IRC job? In other words, if I get some convergence problem (like '? Error  ? No convergence  ? The problem occurs in rhfpro ') in an optimization step of IRC, can I restart my IRC from where it stuck?<br>
<br>Here is an example:<br><br>*** INPUT (part of it)<br> basis=aug-cc-pV(T+d)Z<br> rhf,maxdis=50,maxit=100;<br> rccsd(t),maxit=70,thrden=1.d-6,thrvar=1.d-10;<br> {optg,root=2,method=qsd,maxit=100,saveact=TS3,rewind;print,history}<br>
 {optg,method=qsdpath,dir=+1,numhess=1,hesscentral,maxit=100,saveact=TS3_IRC;print,history}<br>****<br><br>*** OUTPUT (part of it)<br><br> PROGRAM * OPT (Geometry optimization)     Authors: F. Eckert and H.-J. Werner<br><br>
 Geometry optimization using default procedure for command RCCSD(T)<br><br> Geometry written to block  1 of record 700<br><br> Optimized active variables along the reaction path will be saved in file ts3_irc.act<br><br> Numerically approximating hessian using central energy differences<br>
<br> Task list generated. Total number of displacements:     42<br>(...)<br><br> Numerical RCCSD(T) hessian completed. CPU-time: 58207.17 sec, Elapsed: 59983.65 sec<br><br> RCCSD(T) hessian saved to record  5301.2<br><br>
 Combined Powell-Murtagh-Sargent Update of Hessian<br><br> Quadratic Steepest Descent -  Reaction Path Following using exact Hessian<br><br> Hessian eigenvalues:    -0.720210  0.045186  0.086122  0.220480  0.252733  0.333235<br>
<br> QSDPATH1: Starting at a critical point. Gradient norm=  0.44D-04  Stepping along the transition vector, idir =   1<br><br> Optimization point 1<br><br> Variable                                        Last           Current                Next              Gradient           Hessian<br>
<br> E(RCCSD(T)) / Hartree       0.00000000  -548.40580762     0.00000000<br> R1 / ANG                             0.00000000     1.68000597       1.67535167    -0.00008214    -0.06944810<br> R2 / ANG                             0.00000000     1.58945503       1.59220702    -0.00000047     0.46843406<br>
 A / DEGREE                       0.00000000    66.05724619     66.95062670    -0.00000006    -0.00013657<br> R3 / ANG                            0.00000000     1.35229995        1.35212903     0.00000623     0.88658757<br>
 B / DEGREE                       0.00000000   102.58308447   102.51347761     0.00000002     0.00006953<br> G / DEGREE                      0.00000000    90.11384708      90.00488570     0.00000005     0.00002365<br> Convergence:                     1.00000000  (line search)           0.01878095     0.00004385  (total)<br>
<br> Numerically approximating hessian using central energy differences<br><br> Task list generated. Total number of displacements:     42<br><br>(...)<br><br> Numerical RCCSD(T) hessian completed. CPU-time: 58106.44 sec, Elapsed: 59815.04 sec<br>
<br> RCCSD(T) hessian saved to record  5301.2<br><br> Hessian eigenvalues:    -0.603756  0.044188  0.077717  0.215977  0.252942  0.332157<br><br> Performing a regular QSD step. Stepsize =  0.135181    Curvature = .14652D+01<br>
Optimization point 2<br><br> Variable                                      Last           Current        Next           Gradient       Hessian<br><br> E(RCCSD(T)) / Hartree    -548.40580762  -548.40592241     0.00000000<br>
 R1 / ANG                               1.68000597     1.67535167     1.63672546     0.01118126    -0.06876999<br> R2 / ANG                               1.58945503     1.59220702     1.61238313    -0.00547148     0.53891992<br>
 A / DEGREE                       66.05724619    66.95062670    73.54907404    -0.00015855    -0.00010933<br> R3 / ANG                              1.35229995     1.35212903     1.35084905     0.00036726     0.88529322<br>
 B / DEGREE                     102.58308447   102.51347761   101.91805140     0.00001545     0.00006969<br> G / DEGREE                       90.11384708    90.00488570    89.25817619     0.00001837     0.00002126<br> Convergence:                        0.00000000  (line search)     0.14257717     0.01130670  (total)<br>
<br> Numerically approximating hessian using central energy differences<br><br> Task list generated. Total number of displacements:     42<br>(...)<br><br> Numerical RCCSD(T) hessian completed. CPU-time: 50556.55 sec, Elapsed: 52471.89 sec<br>
<br> RCCSD(T) hessian saved to record  5301.2<br><br> Hessian eigenvalues:    -0.132078  0.038530  0.146748  0.203447  0.251917  0.334504<br><br> Performing a regular QSD step. Stepsize =  0.108723    Curvature = .35494D+01<br>
<br> Optimization point 3<br><br> Variable                      Last           Current        Next           Gradient       Hessian<br><br> E(RCCSD(T)) / Hartree    -548.40592241  -548.40943457     0.00000000<br> R1 / ANG                               1.67535167     1.63672546     1.58902162      0.04235023     0.24875090<br>
 R2 / ANG                               1.59220702     1.61238313     1.61361588      0.00201373     0.84044207<br> A / DEGREE                       66.95062670    73.54907404    78.25132174    -0.00033263     0.00000493<br>
 R3 / ANG                              1.35212903     1.35084905     1.35035885       0.00052066     0.88601265<br> B / DEGREE                     102.51347761   101.91805140   100.67110349     0.00011472     0.00007094<br>
 G / DEGREE                       90.00488570    89.25817619    88.29840320     0.00006811     0.00001246<br> Convergence:                        0.00000000  (line search)         0.12498993     0.03041555  (total)<br> ? Error<br>
 ? No convergence<br> ? The problem occurs in rhfpro<br>****<br><br>I will appreciate very much any help.<br><br>Best regards,<br><br>Gabriel<br>