How to save selfconsistent_configurations for every voltage

[ATK-user-zuox]

Dear sir:        Recently i tested to  restart I-V calculations from a checkpoint . i learned from http://quantumwise.com/forum/index.php?topic=3306.msg15142#msg15142 andhttp://quantumwise.com/forum/index.php?topic=1358.msg9062#msg9062 about how to restart a suspended job.i modify the code as

Code

# -------------------------------------------------------------
# IV Curve
# -------------------------------------------------------------
calculator=device_configuration.calculator()

biases = [0.000000, 0.100000, 0.200000, 0.300000, 0.400000, 0.500000,
          0.600000, 0.700000, 0.800000, 0.900000, 1.000000]*Volt
for bias in biases:
    calculator=calculator(
            electrode_voltages=(bias/2, -bias/2))

    device_configuration.setCalculator(
          calculator(),
          initial_state=device_configuration)
    device_configuration.update()
    nlsave("ivcurve_selfconsistent_configurations.nc", device_configuration)
    
#----------------------------------------
# Transmission spectrum
#----------------------------------------
configurations = nlread('ivcurve_selfconsistent_configurations.nc', DeviceConfiguration)
     for device_configuration in configurations:
         transmission_spectrum = TransmissionSpectrum(
             configuration=device_configuration,
             energies=numpy.linspace(-2,2,201)*eV,
             kpoints=MonkhorstPackGrid(4, 4),
             energy_zero_parameter=AverageFermiLevel,
             infinitesimal=1e-06*eV,
             self_energy_calculator=RecursionSelfEnergy(),
             )
         nlsave("TS_analysis.nc", transmission_spectrum)
         nlprint(transmission_spectrum)

. So here is my idea: For the initial calculation script(not restaring script) i want to use "nlsave" statement to make a new file for each converged bias and calculate the transmission spectrum for each bias using each converged bias(i want to exactly know output bias file and restart from it ), my problem is : How to modify the above code in the I-V and transmission module  to realise the these two underlined functions.

[Jess Wellendorff]

Perhaps this code is what you need:

Code

# -------------------------------------------------------------
# IV Curve
# -------------------------------------------------------------
calculator = device_configuration.calculator()

biases = [0.000000, 0.100000, 0.200000, 0.300000, 0.400000, 0.500000,
          0.600000, 0.700000, 0.800000, 0.900000, 1.000000]*Volt

files = []
for bias in biases:
    myfile = "iv_%.3fV" % bias
    files.append(myfile)
    
    calculator=calculator(
            electrode_voltages=(bias/2, -bias/2))
    device_configuration.setCalculator(
          calculator(),
          initial_state=device_configuration)
    device_configuration.update()
    nlsave(myfile, device_configuration)

#----------------------------------------
# Transmission spectrum
#----------------------------------------
for myfile in files:
    device_configuration = nlread(myfile, DeviceConfiguration)[0]

    transmission_spectrum = TransmissionSpectrum(
        configuration=device_configuration,
        energies=numpy.linspace(-2,2,201)*eV,
        kpoints=MonkhorstPackGrid(4, 4),
        energy_zero_parameter=AverageFermiLevel,
        infinitesimal=1e-06*eV, 
        self_energy_calculator=RecursionSelfEnergy(),
        )
    nlsave(myfile, transmission_spectrum)  
    nlprint(transmission_spectrum)

[ATK-user-zuox]

Thanks for your kind reply , i whill check  it  tonight .I have already  solved  it in another way ,the code is :

Code

# -------------------------------------------------------------
# IV Curve
# -------------------------------------------------------------
calculator=device_configuration.calculator()

biases = [0.000000, 0.100000, 0.200000, 0.300000, 0.400000, 0.500000,
          0.600000, 0.700000, 0.800000, 0.900000, 1.000000]*Volt
for bias in biases:
    calculator=calculator(
            electrode_voltages=(bias/2, -bias/2))

    device_configuration.setCalculator(
          calculator(),
          initial_state=device_configuration)
    device_configuration.update()
    nlsave("ivcurve_selfconsistent_configurations_bias_%g.nc" % bias.inUnitsOf(Volt), device_configuration)
    
#----------------------------------------
# Transmission spectrum
#----------------------------------------
for bias in biases:
    configurations = nlread('ivcurve_selfconsistent_configurations_bias_%g.nc' % bias.inUnitsOf(Volt), DeviceConfiguration)
    for device_configuration in configurations:
           transmission_spectrum = TransmissionSpectrum(
               configuration=device_configuration,
               energies=numpy.linspace(-2,2,201)*eV,
               kpoints=MonkhorstPackGrid(4, 4),
               energy_zero_parameter=AverageFermiLevel,
               infinitesimal=1e-06*eV,
               self_energy_calculator=RecursionSelfEnergy(),
               )
           nlsave("TS_analysis.nc", transmission_spectrum)
           nlprint(transmission_spectrum)

This way to save the checkpoint is very helpful and it's easy to restart from the I-V converged state .Hope it could help the new learnrers.

[Anders Blom]

That's a really excellent suggestion!!!