QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: manoj on May 7, 2016, 11:00

Title: regarding the warning while calculation
Post by: manoj on May 7, 2016, 11:00
warning show -calculation did not converge to  requested tolerance , but  data is saved after calculation, Is my data is accurate or not?
Title: Re: regarding the warning while calculation
Post by: Petr Khomyakov on May 7, 2016, 13:21
It really depends on what you mean by 'accurate'. If you want the accuracy given by the tolerance you have set for that calculation, it is not accurate yet, and you then need to do more iterations to achieve the accuracy required.

On the other hand, it might be that the accuracy of physical quantities of interest is already sufficient for making reliable conclusions on the problem of your study. It is only up to you to decide on it.

The warning is only to tell you that the tolerance criteria required by you is not achieved in a given number of iterations, but it might be that this setting is too strict or there is a convergence problem.  In both cases, you may try increasing the maximum number of iterations to see how the total energy of your system converges with respect to the iteration number.