Re: [Wien] No convergence during Volume Optimization

2016-11-14 Thread Abderrahmane Reggad
Thank you Prof Laurence for your answer As I said in my answer to Dr Pieper I have resolved the problem by using another cell parameters and with other points. This problem happens usually when doing volume optimization and I my procedure to resolve the problem was to delete the points with

Re: [Wien] No convergence during Volume Optimization

2016-11-14 Thread Laurence Marks
Did you check how many iterations were used? By default with MSR1 it is 40, you probably needed nothing more than increasing this by using -i 80 (for instance). On Mon, Nov 14, 2016 at 3:38 PM, Abderrahmane Reggad wrote: > Thank you Dr Pieper for the rich information. > >

Re: [Wien] No convergence during Volume Optimization

2016-11-14 Thread Abderrahmane Reggad
Thank you Dr Pieper for the rich information. Yes I have a antiferromagnetic material and for the convergence problem ; the calculation jumps to the next point before reaching the energy criteria (foe example with energy criteria of 0.0001 , it jumps when reaching energy difference of 0.0008 ).

Re: [Wien] No convergence during Volume Optimization

2016-11-14 Thread pieper
The 'difference between energy and force approaches' is just that: a different approach to find the equilibrium positions in space for the atoms and their electrons within the structural model given by the .struct file. The equilibrium is the energy minimum in the parameter space under

Re: [Wien] No convergence during Volume Optimization

2016-11-13 Thread Abderrahmane Reggad
Thank you Dr Pieper for your interesting to my questions. I have optimized the atomic positions before doing calculation. Tha thing that I didn't understand is that the convergence is reached for some points but not for others. For the "optimization notes " , there is no mention on the

Re: [Wien] No convergence during Volume Optimization

2016-11-12 Thread pieper
Look at the curve energy vs. volume and decide yourself wether its worth the while to increase the number of iterations (assuming that's the reason for the 'jump to the next point'). It also is a good idea to look for reasons why the convergence is slow (problem in the struct file? Bad

[Wien] No convergence during Volume Optimization

2016-11-12 Thread Abderrahmane Reggad
Dear Wien Users Sometimes , It happens that during volume optimization , the calculation doesn't converge to the chosen energy criteria and jumps to the next point . In this case, should we delete this point and choose another point or we could accept this calculation. For example , with energy