QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: Sabyasachi Sen on May 9, 2015, 09:00

Title: increased number steps-does not work to overcome convergence proble
Post by: Sabyasachi Sen on May 9, 2015, 09:00

I have used following commands to overcome convergence problems,
"
#----------------------------------------
# Iteration Control Settings
#----------------------------------------
left_electrode_iteration_control_parameters = IterationControlParameters(
    damping_factor=0.5,
    max_steps=120,
    tolerance=0.001,
    number_of_history_steps=25,
    )

right_electrode_iteration_control_parameters = IterationControlParameters(
    damping_factor=0.5,
    max_steps=120,
    tolerance=0.001,
    number_of_history_steps=25,
    )

device_iteration_control_parameters = IterationControlParameters(
    damping_factor=0.5,
    max_steps=120,
    tolerance=0.001,
    number_of_history_steps=25,
    )
   
"

However, it shows convergence error with following commands,

------------------------------------------------------------------------------+
|  99 E = -360.947 dE =  1.548518e-03 dH =  4.940824e-03                       |
+------------------------------------------------------------------------------+
################################################################################
#                                                                              #
# Warning: The calculation did not converge to the requested tolerance!        #
#                                                                              #
################################################################################
+------------------------------------------------------------------------------+
|                                                                              |
Therefore, increase of number of steps not all has any impact to improve to sort out the convergence problem. This problems are more at a higher bias in loop run of I-V calculation.

Kindly help me.

Title: Re: increased number steps-does not work to overcome convergence proble
Post by: Nordland on May 11, 2015, 09:43

Try increasing the electrode temperature.