Calculation ends before EDIFFG is reached
Posted: Wed Jul 11, 2007 5:17 pm
I am doing a spin-polarized calculation with LDA+U for a 10 atom system.
To optimize the atomic postitions, I am using the settings:
EDIFF = 1e-5
EDIFFG = -1e-4
NSW = 200
ISIF = 2
IBRION = 2
However, the calculation terminates after a small number, ~20-50, of iterations while the largest magnitude total force on an atom is larger than 1e-4 eV/Angstrom. For example, it may quit after 24 iterations while the force on a given atom is -0.03 eV/Angstrom. My understanding, based on the manual, is that this calculation should not stop until the absolute value of the largest force is smaller than 1e-4 eV/Angstrom.
Please could you help explain, why might the calculation be stopping before EDIFFG is reached?
Thanks for your help,
AH
To optimize the atomic postitions, I am using the settings:
EDIFF = 1e-5
EDIFFG = -1e-4
NSW = 200
ISIF = 2
IBRION = 2
However, the calculation terminates after a small number, ~20-50, of iterations while the largest magnitude total force on an atom is larger than 1e-4 eV/Angstrom. For example, it may quit after 24 iterations while the force on a given atom is -0.03 eV/Angstrom. My understanding, based on the manual, is that this calculation should not stop until the absolute value of the largest force is smaller than 1e-4 eV/Angstrom.
Please could you help explain, why might the calculation be stopping before EDIFFG is reached?
Thanks for your help,
AH