Messages

1

General Questions and Answers / Re: how to print LDOS ?

« on: February 22, 2010, 11:35 »

thanks for ur reply zh
i m referring page 5 in the paper majority and minority spin density of states referred to as LDOS for layers . how want to know can we do it in atk and how?

2

General Questions and Answers / Re: how to print LDOS ?

« on: February 12, 2010, 11:30 »

hi zh ,
thanks for ur suggestion .
but i want to know how to plot LDOS for particular atoms to obtain graphs as results shown in
volume 62, number 6 physical review B .
 in particular i want to know how and where to specify the position for which LDOS is to be calculated in the calculate LDOS function in atk.
please help !

3

General Questions and Answers / Re: what is the difference in properties of following two structures

« on: February 7, 2010, 06:42 »

thanks Zh,
but actually i wanted to know what difference it makes if the terminations of right and left electrodes r not identical as in the two geometries i had attached .
because when we use scripting we get identically terminated electrodes but in atomic manipulator it is not so and what difference this makes this i wanted to know .
namrata

4

Future Releases / Re: What is your Linux distribution?

« on: February 1, 2010, 05:40 »

I use both Ubuntu 8.04 and Slackware 13.0

But I want to use VNL in "Slackware"

5

General Questions and Answers / how to print LDOS ?

« on: January 31, 2010, 08:30 »

hello everyone ,
like we get the values of DOS for given energies using nlPrint command why dont we get the values of LDOS for the given energy by using the same command.
or in general how to obtain the values of LDOS for desired energy 
namrata

6

General Questions and Answers / what is the difference in properties of following two structures

« on: January 9, 2010, 14:01 »

hello everyone
can someone tell me what is the different between following two electrodes
1] the Z-A-Z script electrodes attached [2009.06 version]
2] the electrodes prepared using 2008.10 from graphene nanoribbon script on Quantumwise website

7

General Questions and Answers / how to convert a 2009.06 geometry setup to 2008.10

« on: January 9, 2010, 12:16 »

hello everyone ,
i got a script from the web for a two probe geometry setup for version 2009.06 but i m currently familiar with 2008.10 version only i want to convert that script to 2008.10 how do i do that ?
i tried using co ordinates but was not able to define equivalent atoms properly , is there some trick to easily find this from the 2009.06 script ?

8

General Questions and Answers / no bond between oxygen and Fe right electrode in the MTJ ????

« on: December 25, 2009, 08:33 »

hello everyone ,
 first of all i would like to know why there is no bond between oxygen from MgO to the right electrode as it is there to the left electrode in fe-mgo-fe mtj default view

calculations for the default view go on smoothly without any error but when i dont make bonds for other systems i get an error
NLPolicyError :atomic_configuration  why

9

General Questions and Answers / ATKError: inverse(DZMatrix const &) : Could not LU factorize!

« on: December 23, 2009, 12:56 »

hello everyone ,

scf calculation of my two probe system does not converge and gives and error 1 in between the scf output and  scf calculations ends giving error 2.

1]# Pulay mixing inversion failed. Using only last step.

2]ATKError: inverse(DZMatrix const &) : Could not LU factorize!
 

10

General Questions and Answers / Re: shifting unit cell along an axis after shifting an electrode along that axis

« on: December 13, 2009, 07:39 »

hello zh
thanks for ur reply
one more query plz

you mean that whether electrode atoms are there inside the unitcell or not that has no effect on the scf calculations ??

but i have seen the z shaped graphene nanoribbon script on the wesite in it the right electrode is shifted and both the unitcells left and right are elongated to encorporate all atoms of both the electrodes. so , i was trying that all atoms of my electrodes are there inside the unitcell.

please clarify i m a beginer .

11

General Questions and Answers / Re: shifting unit cell along an axis after shifting an electrode along that axis

« on: December 13, 2009, 04:31 »

hello
i shifted my two probe system's right electrode in x direction using X_shift in right electrode coordinates . so , the right electrode atoms moved out of the right electrode unitcell. to cover atoms by the unitcell i tried elongating my left and right unit cell along x axis but when i did this the electrode repetitions got separated and my electrodes got distorted .
i think u have got what i want ?
plz help!!

12

General Questions and Answers / shifting unit cell along an axis after shifting an electrode along that axis

« on: December 12, 2009, 12:24 »

hello everyone ,
i have already shifted one electrode along the desired axis but there is problem in shifting the unit cell along with the electrode . plz help !!

13

General Questions and Answers / advanced geometry setup script to the traditional one

« on: November 27, 2009, 08:13 »

hello everyone ,
the zshape_graphene.py is an advanced geometry set up two probe script available at the quantwise website . i wanted to edit some atoms and positions which i can do when i have a two probe script from the atomic manipulator{traditional script}.
 so how to convert that advanced script to the traditional one ? can anyone tell me .

thanks in advance

14

General Questions and Answers / Re: what is default meshcutoff???

« on: November 14, 2009, 11:25 »

thanks a lot

15

General Questions and Answers / what is default meshcutoff???

« on: November 8, 2009, 10:56 »

if i do not specify mesh cutoff in atk 2008.10 scf calculation input file even then the scf calculation gets executed and scf.nc file is generated . what is the default value of mesh cutoff  taken into consideration