CCL:G: Estimated job time in Gaussian

[Detlev Conrad Mielczarek <detlevcm_._googlemail.com>]

 Sent to CCL by: Detlev Conrad Mielczarek [detlevcm_._googlemail.com]
Estimating compute times is its own area of research and typically
 very
 hard to do - not just in ab initio quantum chemistry but also in other
 fields, say CFD.
Under certain circumstances, it is possible to look at the time used
 for
 the initial iterations and thus extrapolate the required time for a set
 number of iterations to get a rough idea. E.g. if I know I complete 200
 CFD iterations a day, I will possibly do 1000 in 5 days.
Having said that, CFD convergence is possibly a lot more
 straightforward
 than ab initio calculations.
 Just the choice of method and basis will have a dramatic impact on the
 calculation time. Then small perturbations in the starting geometry can
 equally impact the calculation time for more complex geometries as its
 can impact the trajectory selected during the optimization.
For very simple molecules, it may be possible to establish
 correlations
 and thus make accurate predictions, but these simple molecules will
 either require seconds (for teaching purposes with simple methods and
 small basis sets) or be subject to very high accuracy calculations in
 research where time matters less.
 Still, this could be a subject for a research project...
 Detlev
 ORCiD 0000-0002-4720-353X
 On 31/12/2021 23:14, Andrew DeYoung andrewdaviddeyoung*gmail.com wrote:
>  Sent to CCL by: "Andrew  DeYoung" [andrewdaviddeyoung\a/gmail.com]
>  Hi,
>  Does anyone know if it is possible for the Gaussian package to estimate the
>  time remaining in a relatively pedestrian calculation (e.g., Opt Freq)?  I'm
>  not seeing a discussion of this in the documentation.  I'm running Gaussian
>  2016 (G16).
>  Thanks in advance for any insight you can provide,
>  Andrew
>  Andrew DeYoung, PhD
>  Department of Chemistry
>  Carnegie Mellon University
>  andrewdaviddeyoung###gmail.com>