An initial set of three vectors, specified in real space by rprim or as unit vectors with angles angdeg , are dimensioned in a second step using scaling factors as specified by acell or by rescaling their cartesian coordinates, as specified by scalecart. The most detailed explanation can be found by looking at rprim. R3 to be positive. If it is not the case, exchange two of them with the associated reduced coordinates. More information about the way the real space lattice, the reciprocal lattice, and symmetries are defined in ABINIT can be found here.
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Purpose : The purpose of this program is to provide an easy way to rapidly plot band structures from Abinit output files. Requirements : Before using the program, you need to have the python interpreter installed on your computer as well as the numerical python extension.
To do so, you must execute the program and specify the name of the. You can specify a group of successive datasets by entering two numbers separated by a minus sign, the two numbers being respectively the number of the first and the last dataset of the group. For example : 1,,8 means that you want to extract datas from datasets 1,3,4,5,6 and 8.
Once the datasets are entered correctly, the program will extract all the nec- essary datas and produce a. Edit the. A dotted line will be placed on your graph at the fermi level. In that case, the fermi energy will take the value of the highest energy eigenvalue present in the HOMO band.
Special k-points are k-points situated at each end of k-directions along which you want to calculate the band structure. Special k-points usually corre- sponds to the vertices of the Brillouin zone. Each line in this section contains the caption and the reduced coordinates of the k-point. The reduced coordinates are to be multiplied 2 by the reciprocal vectors to give the position of the k-point in the Brillouin zone. The caption of the k-point, written between braces, determines the letter or the symbol that will be plotted on the graph to represent this k-point.
All captions in the. The second letter can be any alphabet letter lower of upper case. It consists on a serie of k-points, identified by their respective caption, separated either by "-" minus sign or by " " empty space. For each group of two captions separated by a minus sign, the program will plot a band structure using all the appropriate k-points available in the database between the two corresponding k-points.
If you leave an empty space between two captions, the program will leave an empty space in the graph allowing you to plot many disconnected k-directions on the same graph. Note that all captions used to specify the band structure scheme must be de- fined in the special k-points section.
The database contains a list of k-points reduced coordinates and associated en- ergy eigenvalues in eV. The database key contains multiple informations regarding the system geometry and convergence criteria used to calculate energy eigenvalues of each k-point.
In order for the band structure graph to be valid, it is important that all k- points plotted had their energy eigenvalues obtained from the same system and calculated using the same convergence criteria.
Before adding any datas to the database, such a key is calculated for each dataset and compared to the database key. STEP 3 : produce a. To produce a. You will also be asked to enter the xmgrace launch command, which is the command you usually write in your shell to launch xmgrace default is xmgrace. Line color setup : Add the keyword -setlinecolor in the command line to choose the color of energy bands default is blue for the valence bands ; red for the conduction bands.
The 16 colors recognized by xmgrace are : white, black, red, green, blue, yellow, brown, grey, violet, cyan, magenta, orange, indigo, maroon, turquoise, green4 Line width setup : Add the keyword -setlinewidth in the command line to choose the thick- ness of energy band lines, Fermi energy line and separator lines default is 1 for energy band lines ; 1 for Fermi energy line ; 1 for separator lines.
Empty space s width setup : Add the keyword -setspacewidth in the command line to choose the percent- age of the total graph width to be occupied by empty space s , if any. Empty spaces are empty regions of the graph laid between disconnected k-directions in the band structure. Remember that you can place such empty spaces by putting a " " empty space instead of a "-" minus sign between two captions in the band structure scheme section of the.
Global setup : Add the keyword -setup in the command line if you want to perform a global setup and set all the available options mentionned above in the same run. Restore default setup : Add the keyword -setdefault in the command line to restore the default setup.
While the debug mode is activated, many informations otherwise unseen will be printed on the screen during the execution. This feature is useful if you want to keep a trace of what the code does. It is also a good way to locate exactly where bugs happen, if any.
ABINIT vs VASP Round 2
Mezik We will define by hand the occupation of each spin, see the input variables occopt to be set to 2and occ. The k—points coordinates are given in kptgw. Note that all captions used to specify the band structure scheme must be de- fined in the special mahual section. The trade—off between accuracy and computational efficiency is present in many places in the code, and addressed briefly at the end of the present help file.
ABINIT MANUAL PDF
Shakara These points are used either to sample the Brillouin zone, or to build a band structure along specified lines. See the input bainit istwfk. Is the energy likely more converged than toldfe? Although evaluated at zero frequency, it is understood that the ionic response is not included. In particular, it will be questionable for strongly inhomogeneous systems!
Usually one runs the command with a pipe of standard output to a log file, which can be inspected for warnings or error messages if anything goes wrong or otherwise can be discarded at the end of a run. No error message is reported in the latter file. On the other hand, this is the file that is usually kept for archival purposes. These three sets of data are stored in unformatted binary files native Fortran , or in NetCDF format. An analysis of geometry can also be provided GEO file. What does the code do?
Purpose : The purpose of this program is to provide an easy way to rapidly plot band structures from Abinit output files. Requirements : Before using the program, you need to have the python interpreter installed on your computer as well as the numerical python extension. To do so, you must execute the program and specify the name of the. You can specify a group of successive datasets by entering two numbers separated by a minus sign, the two numbers being respectively the number of the first and the last dataset of the group. For example : 1,,8 means that you want to extract datas from datasets 1,3,4,5,6 and 8. Once the datasets are entered correctly, the program will extract all the nec- essary datas and produce a.