[QE-users] Issue with "WARNING: bfgs curvature condition failed, Theta= 0.667"

[Ning ZHANG]

Dear QE users and community,

My DFT calculation showed a warning message "WARNING: bfgs curvature 
condition failed, Theta= 0.667" when I use the bfgs in the input file. 
The total energy in the output decreases up to the last step, but the 
final total energy jumpes back to a higher value. It is as following:

!    total energy              =   -2468.02677551 Ry
!    total energy              =   -2468.02679297 Ry
!    total energy              =   -2468.02681105 Ry
!    total energy              =   -2468.02683017 Ry
!    total energy              =   -2468.02684879 Ry
!    total energy              =   -2468.02686700 Ry
!    total energy              =   -2468.02688590 Ry
!    total energy              =   -2468.02681513 Ry

When I changed the bfgs to damp, it works good, however, the calculation 
converges slowly, it looks like it will take much more time than bfgs to 
finish the calculation. Is it possible to use bfgs without getting this 
warning problem? (Because I think this warning cannot be ignored)

I would very appreciate it if you can provide me with some advice. 
Thanks for your time.

Best regards,

Ning Zhang