Messages

1

General Questions and Answers / Re: How to reduce memory usage

« on: Today at 06:17 »

229 atoms is not a lot, but when you use MPI parallelization the memory duplication can be quite large. So the main suggestion is to reduce MPI and use more threading.

It works!
Thanks for reply!

2

General Questions and Answers / How to reduce memory usage

« on: October 2, 2024, 14:44 »

Hello!
I am currently calculating a structure with 229 atoms in the central region with spin orbit coupling.
My server have 96 cores 512G ram
The MPI setting number of  processors is 64.
When atk calculates the central region, the memory usage will be insufficient.
Besides turning off SOC, is there any other way to reduce memory usage?
Thanks!

3

Installation and License Questions / Re: Error in open quantumatk

« on: September 27, 2024, 10:14 »

Thanks!
TSRI give me wrong file .
After I try symbolic link /uesr and /usr , I can open quantumatk!
Thanks again!

4

Installation and License Questions / Error in open quantumatk

« on: September 25, 2024, 15:56 »

Hello,
I am have some problem on opening quantumatk.
My linux version is Centos8 and the python version is 3.6.8
I get atk file from TSRI website
I can source the file which is /usr/cad/synopsys/CIC/qatk.cshrc
But open quantumatk , it have some error, it is like:
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""'
[root@512 synopsys]# quantumatk
/usr/cad/synopsys/qatk/cur/bin/quantumatk: /cad/synopsys/qatk/2023.12/atkpython/ bin/quantumatk: /user/cad/synopsys/qatk/2023.12/quantumatk/V-2023.12/atkpython/bin/python3.11 :bad interpreter: no such file or directory
/usr/cad/synopsys/qatk/cur/bin/quantumatk:line 66: /cad/synopsys/qatk/2023.12/atk python/bin/quantumatk:success
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""'
So,Need I upgrade the python version? , or need I delete all the atk file and install atk again?
Thanks!

5

General Questions and Answers / Re: How to Restart a stopped calculation(iv_characteristics)

« on: August 2, 2024, 04:58 »

Thank yuo!
I got it

6

General Questions and Answers / Re: How to Restart a stopped calculation(iv_characteristics)

« on: July 30, 2024, 05:16 »

Thanks for your helping!
My situation is a bit complicated.
My iv_characteristics just set one voltage point(vds_-0.05_vgs_0.00)
The voltage point is running SCF(200steps),it is not converged.
I have used checkpoint handler.
So i rerun the script,will it restarts from 200steps or starting a new calculation?
Thanks!

7

General Questions and Answers / How to Restart a stopped calculation(iv_characteristics)

« on: July 29, 2024, 14:32 »

Hello everyone.

I want to restart a calculation
I find this in quantumatk tutorial
https://docs.quantumatk.com/tutorials/restarting_calculations/restarting_calculations.html
It says I need to add the line
"device_configuration = nlread("checkpointfile.hdf5")[0]"
before
"device_configuration.update()"

But my script is like this:
# Set up configuration
central_region = BulkConfiguration(
    bravais_lattice=central_region_lattice,
    elements=central_region_elements,
    cartesian_coordinates=central_region_coordinates
    )

# Add metallic region
metallic_region_0 = BoxRegion(
    -0.7*Volt,
    xmin = 0.0*Angstrom, xmax = 0.9*Angstrom,
    ymin = 0.0*Angstrom, ymax = 5.6*Angstrom,
    zmin = 13.0*Angstrom, zmax = 90.0*Angstrom,
)

metallic_region_1 = BoxRegion(
    -0.7*Volt,
    xmin = 25.5*Angstrom, xmax = 26.31*Angstrom,
    ymin = 0.0*Angstrom, ymax = 5.6*Angstrom,
    zmin = 13.0*Angstrom, zmax = 90.0*Angstrom,
)

metallic_regions = [metallic_region_0, metallic_region_1]
central_region.setMetallicRegions(metallic_regions)

# Add dielectric region
dielectric_region_0 = BoxRegion(
    3.9,
    xmin = 0.9*Angstrom, xmax = 8.9*Angstrom,
    ymin = 0.0*Angstrom, ymax = 5.6*Angstrom,
    zmin = -2.5*Angstrom, zmax = 105.0*Angstrom,
)

dielectric_region_1 = BoxRegion(
    3.9,
    xmin = 17.5*Angstrom, xmax = 25.5*Angstrom,
    ymin = 0.0*Angstrom, ymax = 5.6*Angstrom,
    zmin = -2.5*Angstrom, zmax = 105.0*Angstrom,
)

dielectric_regions = [dielectric_region_0, dielectric_region_1]
central_region.setDielectricRegions(dielectric_regions)

 device_0321_01 = DeviceConfiguration(
    central_region,
    [left_electrode, right_electrode],
    equivalent_electrode_lengths=[2.584, 2.584]*Angstrom,
    transverse_electrode_repetitions=[[1, 1], [1, 1]],
    )
# device_0321_01 = nlread("tmp/dojo0715.hdf5")[0]

# %% Set DeviceLCAOCalculator

# %% DeviceLCAOCalculator

#----------------------------------------
# Exchange-Correlation
#----------------------------------------
exchange_correlation = NCLDA.PZ

k_point_sampling = KpointDensity(
    density_a=1.0*Angstrom,
    density_b=10.0*Angstrom,
    density_c=200.0*Angstrom
)

numerical_accuracy_parameters = NumericalAccuracyParameters(
    density_mesh_cutoff=80.0*Hartree,
    k_point_sampling=k_point_sampling,
    occupation_method=FermiDirac(
        broadening=300.0*Kelvin
    )
)

#----------------------------------------
# Basis Set
#----------------------------------------
basis_set = [
    BasisLDAPseudoDojo.Selenium_Medium,
    BasisLDAPseudoDojo.Rhodium_Medium,
    BasisLDAPseudoDojo.Tungsten_Medium,
    ]



iteration_control_parameters = IterationControlParameters(
    max_steps=3000,
    damping_factor=0.079,
    non_convergence_behavior=StopCalculation()
)

device_algorithm_parameters = DeviceAlgorithmParameters(
    initial_density_type=NeutralAtom(
        electrode_constraint_length=10.0*Angstrom,
        )
)

poisson_solver = MultigridSolver(
    boundary_conditions=[
        [NeumannBoundaryCondition(), NeumannBoundaryCondition()],
        [PeriodicBoundaryCondition(), PeriodicBoundaryCondition()],
        [DirichletBoundaryCondition(), DirichletBoundaryCondition()]
    ]
)

contour_parameters = ContourParameters(
    equilibrium_contour = SemiCircleContour(
        circle_points=40
    )
)

checkpoint_handler = CheckpointHandler(
    file_name='/home/weixiang/tmp/dojo0729.hdf5'
)

calculator = DeviceLCAOCalculator(
    basis_set=basis_set,
    exchange_correlation=exchange_correlation,
    numerical_accuracy_parameters=numerical_accuracy_parameters,
    iteration_control_parameters=iteration_control_parameters,
    device_algorithm_parameters=device_algorithm_parameters,
    poisson_solver=poisson_solver,
    contour_parameters=contour_parameters,
    electrode_voltages=[ 0.  , -0.05]*Volt,
    checkpoint_handler=checkpoint_handler
)
# %% Set Calculator

device_0321_01.setCalculator(calculator)

nlsave('0715_6w_dojo_general_0v_electrode_diele_filled_k1*10_1*100.hdf5', device_0321_01)


# %% IVCharacteristics

kpoints = MonkhorstPackGrid(
    nb=100
)

iv_characteristics = IVCharacteristics(
    configuration=device_0321_01,
    filename='0715_6w_dojo_general_0v_electrode_diele_filled_k1*10_1*100.hdf5',
    object_id='ivc',
    gate_source_voltages=numpy.linspace(0.0, 0.0, 1)*Volt,
    drain_source_voltages=numpy.linspace(-0.05, -0.05, 1)*Volt,
    energies=numpy.linspace(-3.0, 3.0, 101)*eV,
    kpoints=kpoints
)

iv_characteristics.update()

I can't find "device_configuration.update()"
So, I don't know how to insert "device_configuration = nlread("tmp/dojo0715.hdf5")[0]" in my script.
Can anyone help me?
Thanks!

8

General Questions and Answers / Effect of Spin-orbit coupling or noncollinear spin on TMD-FET current

« on: June 16, 2024, 08:40 »

Hello everyone.

I am studying dual gate TMD-FET. I knew before that TMD is a material with strong Spin-orbit coupling.
But my server does not have the ability to enable the calculation with noncollinear spin and Spin-orbit coupling.
I want to know whether Spin-orbit coupling or noncollinear spin has a great influence on the current?

ps. The current refers to the Id-Vg current of iv-characteristics

9

General Questions and Answers / Add dielectric to the electrode region

« on: April 1, 2024, 16:04 »

Hello everyone,
I want to know how to add dielectric to the electrode region,
Because the dielectric of my structure must cover the entire component,
I don't understand why there is a warning "Spatial regions extending into the electrodes are ignored during the electrode calculation"