[molpro-user] new user question on re-using Hessians

[Li, Jun]

As indicated by the error message, your CCSD did not converge.  The
error seems to have nothing to do the reuse of the Hessian.  The CCSD
optimization is numerical and it did not converge at one of the
"displaced" geometries.

Jun Li
----------------------------------------------
Jun Li, PhD, Senior Research Scientist II
MS K8-91, P.O. Box 999, 3335 Q Avenue
Environmental Molecular Sciences Laboratory
Pacific Northwest National Laboratory
Richland, Washington 99352
Tel:  (509)376-4354 (O)
Fax: (509)376-0420 (O)
E-mail: jun.li at pnl.gov
Web: http://emslbios.pnl.gov/id/li_j
----------------------------------------------


-----Original Message-----
From: owner-molpro-user at molpro.chem.cf.ac.uk
[mailto:owner-molpro-user at molpro.chem.cf.ac.uk] On Behalf Of
tsdibble at mailbox.syr.edu
Sent: Thursday, September 01, 2005 6:31 PM
To: molpro-user at molpro.net
Subject: [molpro-user] new user question on re-using Hessians


   I am trying to do a UCCSD geometry optimization while re-using a
B3LYP Hessian.  I would appreciate any help you would be willing to give
this novice user of MOLPRO.  The relevant parts of the input file are:

basis=cc-pVTZ

UKS,B3LYP                        !Call UB3LYP
wf,electrons=34,symmetry=1,spin=2  !triplet  neutral=34 e-'s  C1
symmetry

optg
frequencies
save,5300.2                      ! save Hessian in record 5300.2

hf
wf,electrons=34,symmetry=1,spin=2   ! triplet  neutral  C1 symmetry

uccsd;open,2                ! Switch to UCCSD  use "open" to get triplet
maxit=100                   ! allow extra iterations ??
optg
hstart,5300.2               ! read Hessian
uccsd(t)
---

   The B3LYP opt and frequencies seem to run fine, and I get the RHF and
UCCSD energy.  When it comes to the UCCSD optimization, I get the
following:

 STARTING GEOMETRY OPTIMIZATION FOR UCCSD

 CONVERGENCE THRESHOLDS:  .300D-03 (STEP)  .300D-03 (GRADIENT)  .100D-05
(ENERGY)
 MAX. NUMBER OF STEPS:          50

 Doing optimization in  12 symmetrical displacement coordinates

 Computing numerical gradient for displacement coordinate   1
 ? Error
 ? No convergence
 ? The problem occurs in uccsd
 CURRENT STACK:      CIPRO  MAIN

 GA ERROR termxy

 GA ERROR
0:0:termxy:: 0


   Thanks!
   Ted Dibble

P.S.    I am running on the IBM p690 at NCSA

***************************************************
Theodore S. Dibble           (315) 470-6596
Department of Chemistry      (315) 470-6856 (fax)
SUNY College of Environmental Science and Forestry One Forestry Drive
Syracuse NY 13210        tsdibble at syr.edu
  http://www.esf.edu/chemistry/faculty/dibble.htm
****************************************************