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
--
Dr. Alexey V. Akimov
Postdoctoral Research Associate
Department of Chemistry
University of Rochester
aakimov at z.rochester.edu
