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Topics - davalenciah

Pages: [1]
1
General Questions and Answers / VNL Classsic view on retina macbook
« on: August 1, 2016, 21:58 »
Hello Guys,

I would like to use VNL with the classic view on my retina macbook, but it does not show that option on the view- menu. Do you know how can I switch from project view to classic view.

I attached a screenshot of vnl.

Thanks,

2
General Questions and Answers / Band structure GaAs Huckel
« on: April 15, 2014, 23:45 »
Hello guys,

I am interested in getting the band structure for GaAs using extended Huckel and Cerda-GW parameters; I calculated an energy gap of 1.203 eV, which is significantly lower than the experimental value. Do you have any idea what might cause this error?

Thank you

3
General Questions and Answers / Si Band structure problem
« on: October 2, 2012, 15:27 »
Hello,

I would like to calculate  the band structure for Si Bulk in different routes and I defined the Silicon structure lattice by the unit vectors a,b,c
as it shows in the script. In this way,  the band structure can only be calculated in the "G" and "X" direction. However, if I define my lattice
as:
lattice=FaceCenteredCubic(5.4306*Angstrom)

It calculates the band structure for more directions  as 'W', 'L',  'K',  'U' 
Could you please explain me why I cannot include this routes when I define the lattice by unit vectors.

Thank You

4
General Questions and Answers / Semicore Pseudopotential
« on: December 15, 2011, 20:03 »
Hello

I am running a structure with Lanthanum for GGA and LDA
exchange correlation function as:

for LDA
#----------------------------------------
# Basis Set
#----------------------------------------
basis_set = [
       HGHLDABasis.Lanthanum_HGH_11_DoubleZetaDoublePolarized
   ]
and for GGA

HGHGGAPBEBasis.Lanthanum_HGH_11_DoubleZetaDoublePolarized

and I got a error message
" HGHLDABasis.Lanthanum_HGH_11_DoubleZetaDoublePolarized,
AttributeError: 'module' object has no attribute 'Lanthanum_HGH_11_DoubleZeta' "
 
Could you help me to solve this error?


Thanks

5
General Questions and Answers / Warning Message
« on: November 29, 2011, 14:35 »
Hello

I was doing a DFT transport calculation and I got a message in the output file as:

################################################################################
# WARNING                                                                      #
#                                                                              #
# The computed multigrid residual is greater than the required accuracy.       #
#                                                                              #
# Computed residual :   1.81808e-12                                            #
# Required accuracy :   1.00000e-12                                            #
#                                                                              #
################################################################################

What parameter I should increase to reach the require accuracy?
the mess cut off?
k points or another one?


Thanks for your Help

6
General Questions and Answers / Question about Gate Voltage atk 11.08
« on: November 26, 2011, 00:55 »
Hello

I would like to study the transmission to different gate voltage. making use
extended huckel calculator. I defined my configuration (attached)
and I fallow the manual [/tutorials/latest/GrapheneDevice/index.html/chap.further.html#chap.further.sect1.both]
and I got this message

File "confvg.py", line 2, in <module>
    device_configuration = nlread('conf.nc', object_id='gID000')[0]
  File "./zipdir/NL/IO/NLSaveUtilities.py", line 285, in nlread
  File "./zipdir/NL/IO/NLSaveUtilities.py", line 689, in nlreadDeviceConfiguration
  File "./zipdir/NL/NanoLanguage/ScopeExecuter.py", line 58, in execute
NL.ComputerScienceUtilities.Exceptions.NLScopeExecutionError: Unit missing - please check input.

Thanks for your help !! :o




7
General Questions and Answers / Gaussian Cube Files
« on: September 26, 2011, 18:10 »
Hello,

I am interested in to know the effective potential for a simple configuration
and I exported my data to a grid file ( The grid is written as a Gaussian Cube File              |
 (http://local.wasp.uwa.edu.au/~pbourke/dataformats/cube))
but it is not clear for me how the grid data  is arranged?

can someone suggest me a tutorial to this topic
or explain  me how the data is arranged 


Thanks  ???


8
General Questions and Answers / setMetallicRegions
« on: July 26, 2011, 18:02 »
Hello  ;)

I would like create a gate voltage that include central and electrodes regions

I used something like this but it didn't work  ???

Can anyone help me. Thanks

# Gate at the central region
metallic_region_0 = BoxRegion(
    0.5*Volt,
    xmin = 0*Angstrom, xmax = 20.0*Angstrom,
    ymin = 13.28380098*Angstrom, ymax = 13.78380098*Angstrom,
    zmin = 0.0*Angstrom, zmax = 40.9120017*Angstrom
)
metallic_regions0 = [metallic_region_0]
central_region.setMetallicRegions(metallic_regions0)


# gate at left electrode
metallic_region_1 = BoxRegion(
    0.5*Volt,
    xmin = 0*Angstrom, xmax = 20.0*Angstrom,
    ymin = 13.28380098*Angstrom, ymax = 13.78380098*Angstrom,
    zmin = -8.18240034*Angstrom, zmax = 0.0*Angstrom
)

metallic_regions1 = [metallic_region_1]
left_electrode.setMetallicRegions(metallic_regions1)


device_configuration = DeviceConfiguration(
    central_region,
    [left_electrode, right_electrode]
    )

9
General Questions and Answers / Include two gate voltage
« on: March 10, 2011, 00:22 »
hello

I want to add two voltage gate  to my configuration one button and another at top . I did that independently,  when add both I cannot get them together.
 

Can anyone help me.


Thanks  :D


# Add metallic region
metallic_region_0 = BoxRegion(
    0*Volt,
    xmin = 0*Angstrom, xmax = 37.8315*Angstrom,
    ymin = 15.5864*Angstrom, ymax = 16.0864*Angstrom,
    zmin = 1.527387e+01*Angstrom, zmax = 2.657743e+01*Angstrom
)

metallic_regions0 = [metallic_region_0]
central_region.setMetallicRegions(metallic_regions0)

# Add metallic region
metallic_region_1 = BoxRegion(
    5*Volt,
    xmin = 0*Angstrom, xmax = 37.8315*Angstrom,
    ymin = 25.5864*Angstrom, ymax = 26.0864*Angstrom,
    zmin = 1.527387e+01*Angstrom, zmax = 2.657743e+01*Angstrom
)
metallic_regions1 = [metallic_region_1]
central_region.setMetallicRegions(metallic_regions1)


device_configuration = DeviceConfiguration(
    central_region,
    [left_electrode, right_electrode]
    )

10
General Questions and Answers / How can I know why my process its broked
« on: December 6, 2010, 16:17 »
hello

I was doing IV calculation for graphene and my job it's broken without apparently reason
I just get some transmission values and I was looking for   error message in var/log  but
I could not find memory or hard drive errors

do you know how can I run my process and get an output with errors message?
 
Thanks

11
General Questions and Answers / Plot band structure
« on: March 8, 2010, 18:22 »
Hello

I'm calculating the band structure and energy gap.
I want to plot the different band structure in the same graphics and I used the matplotlib as

from NanoLanguage import *
import pylab


y=bandstructure.evaluate()
x=bandstructure.kpoints()
pylab.figure()
pylab.plot(x,y)

but it did in a wrong way
could someone help me to plot different  band structures in a same graph

Thanks
 

12
General Questions and Answers / error with Trasmission spectrum
« on: January 21, 2010, 18:02 »
I was  doing the calculation of Transmission spectrum to Nananotube of boron nitrogen and
i got this message

Traceback (most recent call last) :
File "/tmp/tmpKEPopJ.nl", line 406, in ?
      runtime_parameters=runtime_parameters
ATKError: #SpeciesContainer::attributes (Atom const & at) : species not found
Terminated Abnormally

could someone help me?

Thanks

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