Molcas Forum

IFK

Member

Registered: 2018-03-09

Posts: 2

CCSD Optimisations & Densities

Hi All,

I'm trying to run a CCSD geometry optimisation and having some difficulties.

Is it possible to perform geometry optimisations w/ CCSD? A CCSD single-point works fine, and the CCSD step works works when I try a geometry optimisation, but the subsequent NUMERICAL_GRADIENT module (via SLAPAF) crashes:

()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()
                            MOLCAS executing module NUMERICAL_GRADIENT with 8000 MB of memory
                                              at 16:14:50 Wed Feb 14 2018
()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()


 Root to use:                     1
 Number of internal degrees                                1
 Number of constraints                                     0
 Number of "hard" constraints                              0
 Number of displacements                                   2
 Effective number of displacements are                     2

      Cholesky vectors         166   96   86   96   57  111  125  111



  Input file to MOLDEN was generated!



  Input file to MOLDEN was generated!

 Numerical_Gradient failed ...
 RASSCF returned with return code, rc =                    96
 for the perturbation iDisp =                     1
--- Stop Module:  numerical_gradient at Wed Feb 14 16:16:35 2018 /rc= _INTERNAL_ERROR_ ---
--- Module numerical_gradient spent 1 minute and 45 seconds 
Non-zero return code - check program input/output
--- Module auto spent 1 minute and 46 seconds 
Non-zero return code - check program input/output
--- Module auto spent 1 minute and 46 seconds 
Non-zero return code - check program input/output
--- Stop Module:  auto at Wed Feb 14 16:16:35 2018 /rc= _INTERNAL_ERROR_ ---
--- Module auto spent 4 minutes and 25 seconds 
--- Stop Module:  auto at Wed Feb 14 16:16:35 2018 /rc= _INTERNAL_ERROR_ ---
--- Module auto spent 4 minutes and 25 seconds 

My input file looks like this (hopefully nothing obviously wrong... quite new to MOLCAS!):

&GATEWAY

 .....

>DoWhile

&SEWARD

 CHOLESKY

 R02O

END OF INPUT

&SCF

 CHOLESKY

 CHARGE
  2
  
END OF INPUT 

&RASSCF

 OUTORBITALS
  CANONICAL

 CHOLESKY

 ....
  
 LINEAR

LUMORB
 OUTORBITALS
  CANONICAL

&MOTRA

 JOBIPH
 
&CCSDT

 CCSD
 
 ITERATIONS
  50
 
 SHIFT
  0.2 0.2
  
 ACCURACY
  1.0d-7  
   
END OF INPUT

&SLAPAF

 ITERATIONS 
  50

END OF INPUT

>EndDo

Additionally, is it possible to get the CCSD density out of a CCSD calculation? Preferably as a .molden file, but a cube file would be workable.

Thanks very much!

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,085

Re: CCSD Optimisations & Densities

In general, codes that require running several modules (like CCSD or RASSI) do not work with numerical gradients, but I believe CHCC(+CHT3) should work.

I don't think you have CC densities, but I may be wrong.

IFK

Member

Registered: 2018-03-09

Posts: 2

Re: CCSD Optimisations & Densities

Ok, thanks Ignacio!