[Pw_forum] speeding up vc-relax

[Nichols A. Romero]

Hi,

I was doing vc-relax on a vdW bonded system. An inherently "floppy"
system that has a very shallow energy minimum. It took about 1000
relaxation steps to find the energy minimum. I
set dt = 10.0 which is probably too low, but I had problems at dt =
100.0 mostly because my starting equilibrium structure was off (The
input parameters where from experiment and the starting pressure
calculated by PWSCF was 10 GPa).

It doesn't look like the BFGS works with the vc-relax algorithm.

Does anyone have any suggestions for speeding up vc-relax?

Thanks,
--
Dr. Nichols A. Romero, PhD.
1613 Denise Dr. Apt. D
Forest Hill, MD 21050
443-567-8328 (C)
410-306-0709 (O)