16
General Questions and Answers / Re: Calculation of IV-curves in Quantumwise
« on: May 28, 2020, 21:39 »
Can you please explain the difference between 'I-V Curve' and 'I-V Characteristics'?
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17
General Questions and Answers / Re: Magnetic moment
« on: May 23, 2020, 01:16 »You should be able to compute magnetic moments using th eMullikenPopulation analysis module (with a spin-polarized DFT calculation): https://docs.quantumwise.com/manuals/Types/MullikenPopulation/MullikenPopulation.html
Hi
Where can I find the link to this tutorial? Old tutorial links are not available I think since the aquisition of quantumwise by synopsys.
18
General Questions and Answers / Re: Differene between zero bias conductance in bulk mode and device mode
« on: May 16, 2020, 20:46 »
I have also faced similar issues many times. For a perfectly periodic structure, transmission can be calculated from unit cell. Device setup is not necessary. But when I create a device by just repeating the same structure along transport axis and converting to device, the transmission spectrum becomes completely different.
19
General Questions and Answers / Re: q dependent dielectric function
« on: May 8, 2020, 18:54 »
Can someone please help me on this?
20
General Questions and Answers / q dependent dielectric function
« on: May 7, 2020, 01:15 »
Hi is it possible to calculate q dependent dielectric function in quantum ATK as done in the paper
"Ab initio study of the dielectric response of crystalline ropes of metallic single-walled carbonnanotubes: Tube-diameter and helicity effects"?
They use Time dependent DFT. If I calculate optical spectrum in quantum ATK, is q value 0 by default?
"Ab initio study of the dielectric response of crystalline ropes of metallic single-walled carbonnanotubes: Tube-diameter and helicity effects"?
They use Time dependent DFT. If I calculate optical spectrum in quantum ATK, is q value 0 by default?
21
General Questions and Answers / Re: Molecular Dynamics at low temperature
« on: May 7, 2020, 01:05 »
Thank you so much.
22
General Questions and Answers / Re: strain on Si
« on: April 20, 2020, 20:31 »
Thank you so much for the response.
23
General Questions and Answers / Re: strain on Si
« on: April 20, 2020, 20:16 »
What is the difference between applying strain by changing lattice parameter and using stretch cell in quantum ATK?
24
General Questions and Answers / Re: calculate strain percentage
« on: April 20, 2020, 20:10 »
What is the difference between moving and stretching atoms along the unit cell?
25
General Questions and Answers / Transmission Spectrum for superconductors
« on: April 16, 2020, 18:34 »
What does the transmission spectrum for a superconductor look like? i.e if it is plotted for below its critical temperature. Does it show infinite transmission coefficient?
26
General Questions and Answers / Molecular Dynamics at low temperature
« on: April 16, 2020, 18:32 »
https://docs.quantumwise.com/casestudies/md_landauer/md_landauer.html
Can we use the method used in this tutorial to calculate transmission spectrum for low temperatures i.e close to 0K?
Can we use the method used in this tutorial to calculate transmission spectrum for low temperatures i.e close to 0K?
27
General Questions and Answers / Re: Negative Mulliken Population
« on: April 14, 2020, 22:51 »
For example, I wrote a simple script above where I calculate Mulliken population for CNT(10,0). Even in this one some shells have negative numbers.
28
General Questions and Answers / Re: Negative Mulliken Population
« on: April 14, 2020, 22:50 »
# -*- coding: utf-8 -*-
# -------------------------------------------------------------
# Bulk Configuration
# -------------------------------------------------------------
# Set up lattice
vector_a = [17.8336117435, 0.0, 0.0]*Angstrom
vector_b = [0.0, 17.8336117435, 0.0]*Angstrom
vector_c = [0.0, 0.0, 4.26258]*Angstrom
lattice = UnitCell(vector_a, vector_b, vector_c)
# Define elements
elements = [Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon,
Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon,
Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon,
Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon,
Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon]
# Define coordinates
fractional_coordinates = [[ 0.719630545292, 0.5 , 0.666666666667],
[ 0.708881061277, 0.567869570979, 0.833333333333],
[ 0.719630545292, 0.5 , 0.333333333333],
[ 0.677684843625, 0.629095595475, 0.666666666667],
[ 0.629095595475, 0.677684843625, 0.833333333333],
[ 0.708881061277, 0.567869570979, 0.166666666667],
[ 0.677684843625, 0.629095595475, 0.333333333333],
[ 0.567869570979, 0.708881061277, 0.666666666667],
[ 0.5 , 0.719630545292, 0.833333333333],
[ 0.629095595475, 0.677684843625, 0.166666666667],
[ 0.567869570979, 0.708881061277, 0.333333333333],
[ 0.432130429021, 0.708881061277, 0.666666666667],
[ 0.370904404525, 0.677684843625, 0.833333333333],
[ 0.5 , 0.719630545292, 0.166666666667],
[ 0.432130429021, 0.708881061277, 0.333333333333],
[ 0.322315156375, 0.629095595475, 0.666666666667],
[ 0.291118938723, 0.567869570979, 0.833333333333],
[ 0.370904404525, 0.677684843625, 0.166666666667],
[ 0.322315156375, 0.629095595475, 0.333333333333],
[ 0.280369454708, 0.5 , 0.666666666667],
[ 0.291118938723, 0.432130429021, 0.833333333333],
[ 0.291118938723, 0.567869570979, 0.166666666667],
[ 0.280369454708, 0.5 , 0.333333333333],
[ 0.322315156375, 0.370904404525, 0.666666666667],
[ 0.370904404525, 0.322315156375, 0.833333333333],
[ 0.291118938723, 0.432130429021, 0.166666666667],
[ 0.322315156375, 0.370904404525, 0.333333333333],
[ 0.432130429021, 0.291118938723, 0.666666666667],
[ 0.5 , 0.280369454708, 0.833333333333],
[ 0.370904404525, 0.322315156375, 0.166666666667],
[ 0.432130429021, 0.291118938723, 0.333333333333],
[ 0.567869570979, 0.291118938723, 0.666666666667],
[ 0.629095595475, 0.322315156375, 0.833333333333],
[ 0.5 , 0.280369454708, 0.166666666667],
[ 0.567869570979, 0.291118938723, 0.333333333333],
[ 0.677684843625, 0.370904404525, 0.666666666667],
[ 0.708881061277, 0.432130429021, 0.833333333333],
[ 0.629095595475, 0.322315156375, 0.166666666667],
[ 0.677684843625, 0.370904404525, 0.333333333333],
[ 0.708881061277, 0.432130429021, 0.166666666667]]
# Set up configuration
bulk_configuration = BulkConfiguration(
bravais_lattice=lattice,
elements=elements,
fractional_coordinates=fractional_coordinates
)
# -------------------------------------------------------------
# Calculator
# -------------------------------------------------------------
k_point_sampling = MonkhorstPackGrid(
nc=6,
)
numerical_accuracy_parameters = NumericalAccuracyParameters(
density_mesh_cutoff=55.0*Hartree,
k_point_sampling=k_point_sampling,
)
calculator = LCAOCalculator(
numerical_accuracy_parameters=numerical_accuracy_parameters,
)
bulk_configuration.setCalculator(calculator)
nlprint(bulk_configuration)
bulk_configuration.update()
nlsave('(10,0) Carbon Nanotube.hdf5', bulk_configuration)
# -------------------------------------------------------------
# Mulliken Population
# -------------------------------------------------------------
mulliken_population = MullikenPopulation(bulk_configuration)
nlsave('(10,0) Carbon Nanotube.hdf5', mulliken_population)
nlprint(mulliken_population)
# -------------------------------------------------------------
# Bulk Configuration
# -------------------------------------------------------------
# Set up lattice
vector_a = [17.8336117435, 0.0, 0.0]*Angstrom
vector_b = [0.0, 17.8336117435, 0.0]*Angstrom
vector_c = [0.0, 0.0, 4.26258]*Angstrom
lattice = UnitCell(vector_a, vector_b, vector_c)
# Define elements
elements = [Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon,
Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon,
Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon,
Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon,
Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon]
# Define coordinates
fractional_coordinates = [[ 0.719630545292, 0.5 , 0.666666666667],
[ 0.708881061277, 0.567869570979, 0.833333333333],
[ 0.719630545292, 0.5 , 0.333333333333],
[ 0.677684843625, 0.629095595475, 0.666666666667],
[ 0.629095595475, 0.677684843625, 0.833333333333],
[ 0.708881061277, 0.567869570979, 0.166666666667],
[ 0.677684843625, 0.629095595475, 0.333333333333],
[ 0.567869570979, 0.708881061277, 0.666666666667],
[ 0.5 , 0.719630545292, 0.833333333333],
[ 0.629095595475, 0.677684843625, 0.166666666667],
[ 0.567869570979, 0.708881061277, 0.333333333333],
[ 0.432130429021, 0.708881061277, 0.666666666667],
[ 0.370904404525, 0.677684843625, 0.833333333333],
[ 0.5 , 0.719630545292, 0.166666666667],
[ 0.432130429021, 0.708881061277, 0.333333333333],
[ 0.322315156375, 0.629095595475, 0.666666666667],
[ 0.291118938723, 0.567869570979, 0.833333333333],
[ 0.370904404525, 0.677684843625, 0.166666666667],
[ 0.322315156375, 0.629095595475, 0.333333333333],
[ 0.280369454708, 0.5 , 0.666666666667],
[ 0.291118938723, 0.432130429021, 0.833333333333],
[ 0.291118938723, 0.567869570979, 0.166666666667],
[ 0.280369454708, 0.5 , 0.333333333333],
[ 0.322315156375, 0.370904404525, 0.666666666667],
[ 0.370904404525, 0.322315156375, 0.833333333333],
[ 0.291118938723, 0.432130429021, 0.166666666667],
[ 0.322315156375, 0.370904404525, 0.333333333333],
[ 0.432130429021, 0.291118938723, 0.666666666667],
[ 0.5 , 0.280369454708, 0.833333333333],
[ 0.370904404525, 0.322315156375, 0.166666666667],
[ 0.432130429021, 0.291118938723, 0.333333333333],
[ 0.567869570979, 0.291118938723, 0.666666666667],
[ 0.629095595475, 0.322315156375, 0.833333333333],
[ 0.5 , 0.280369454708, 0.166666666667],
[ 0.567869570979, 0.291118938723, 0.333333333333],
[ 0.677684843625, 0.370904404525, 0.666666666667],
[ 0.708881061277, 0.432130429021, 0.833333333333],
[ 0.629095595475, 0.322315156375, 0.166666666667],
[ 0.677684843625, 0.370904404525, 0.333333333333],
[ 0.708881061277, 0.432130429021, 0.166666666667]]
# Set up configuration
bulk_configuration = BulkConfiguration(
bravais_lattice=lattice,
elements=elements,
fractional_coordinates=fractional_coordinates
)
# -------------------------------------------------------------
# Calculator
# -------------------------------------------------------------
k_point_sampling = MonkhorstPackGrid(
nc=6,
)
numerical_accuracy_parameters = NumericalAccuracyParameters(
density_mesh_cutoff=55.0*Hartree,
k_point_sampling=k_point_sampling,
)
calculator = LCAOCalculator(
numerical_accuracy_parameters=numerical_accuracy_parameters,
)
bulk_configuration.setCalculator(calculator)
nlprint(bulk_configuration)
bulk_configuration.update()
nlsave('(10,0) Carbon Nanotube.hdf5', bulk_configuration)
# -------------------------------------------------------------
# Mulliken Population
# -------------------------------------------------------------
mulliken_population = MullikenPopulation(bulk_configuration)
nlsave('(10,0) Carbon Nanotube.hdf5', mulliken_population)
nlprint(mulliken_population)
29
General Questions and Answers / Re: Application of an external magnetic field
« on: April 7, 2020, 23:56 »
Hello
I am using 2019 version. Is it possible to apply magnetic fields in 2019 version?
I am using 2019 version. Is it possible to apply magnetic fields in 2019 version?
30
General Questions and Answers / Partial and projected DOS?
« on: April 2, 2020, 19:28 »
I want to know the difference between partial and projected DOS? In DOS analyzer we can select each atom and orbital to show DOS related to that particular atom and/or orbital. Is it the same as partial DOS?