Set cell_factor (in &cell) to a number higher than the default like suggested... That should work.
Cheers, Martin Andersson University of Copenhagen Den 2012-09-23 4:43 PM, Alexey Akimov skrev: > Dear all, > > I'm trying to optimize a relatively large system such as 2 C60 / unit cell. > So i start with relatively large cell dimensions. I'm doing vc-relax > calculations with either 'damp'&'damp-pr' or 'bfgs'&'bfgs' for ionic and cell > dynamics options. However, after some number (~50-70) of successful > (ionic/cell) steps the calculations crash with the error: > > Error in routine scale_h (1): > Not enough space allocated for radial FFT: try restarting with a larger > cell_factor. > > It seems like this happens when the size of the simulation cell changes by > some notable amount with respect to the starting one. Perhaps, the program > automatically changes the plane wave basis set (increases). If i restart the > calculations with the latest (most optimal) configuration of the system and > the same amount of memory allocated, the further optimization can proceed > some more time (also ~50 - 70 steps) before next crash. So in principle it is > still possible to achieve the convergence with this sequence of operations, > but it is quite inconvenient to reset the calculations every 50-70 steps. > > So my question: is there any way to avoid this and get optimized results > without intermediate crashes (apart from increasing the amount of memory > reserved in the beginning)? > > Thank you, > Alexey > >
