ABINIT Discussion Forums

Hi, thanks for the reply. i took the crystal structure from pauling file database for CrB and LaAl, according to the database, both of them are orthorhombic, not rhombohedral. that is the root of my calculation problem. Best regards, jin I think you don't undestand the shape of the unit cell. The ba...

Hi, Emmanuel thanks a lot for your patient help. i got the angdeg, and rprim. put it clear, actually i have the problem with crystal structure. the calculations for CrB and LaAl with the same structure, we can use the same rprim, and same Xred. then how to set up acell? i tested that different acell...

second result using: (CrB lattice parameter) acell 3*10 angstrom rprim 0.12725884 0.33681374 0.00000000 -0.12725884 0.33681374 0.00000000 0.00000000 0.00000000 0.34106412 output: DATASET 1 : space group Cm c m (# 63); Bravais oC (1-face-center ortho.) ================================================...

HI, Emmanuel thank you very much, it solves my problem.but i have another two questions.from these two results, i can see that the Xred is always the same no matter what is the rprim. it is supposed to be the same? secondly, how i can calculate the lattice parameter from the results then? i had the ...

Hi, Emmanuel thanks a lot for your detailed reply, i really appreciate it. i will try these methods immediately. i always have problems seting rprim or angdeg. you suggested either using acell 2*9.531 5.809 bohr angdeg 90 90 41.4 i would like to know how you set up angdeg, if possible. how you get &...

Hi, Emmanuel, the LaAl lattice parameter: a=9.531 b=7.734 c= 5.809, space group: Cmcm (63) , prototype:CrB, Pearson Symbol: oC8. i also have a question, the space group is given based on the conventional cell, right? if so,the crystal structure of the primitive cell could change, and also the space ...

Hi, here is another input file, which i am trying to use spgroup, # dilatmx 1.1 # Maximum scaling allowed for lattice parameters # ionmov 2 # Use BFGS algorithm # ntime 50 # Maximum number of optimization steps # optcell 0 # Fully optimize unit cell geometry, keeping symmetry # tolmxf 5.0e-6 # Conve...

Hi, Emmanuel, thanks a lot for the reply,the following is my input file, # dilatmx 1.1 # Maximum scaling allowed for lattice parameters # ionmov 2 # Use BFGS algorithm # ntime 50 # Maximum number of optimization steps # optcell 0 # Fully optimize unit cell geometry, keeping symmetry # tolmxf 5.0e-6 ...

Hi, sonu, i met exactly the same problems as you for setting up unit cell. did you solve the problem using non-primitive cells? is the calculation correct? i calculated the AlLa structure using the cst.www.nrl.navy.mil website for spacegroup #63 (CrB structure), the output file gives me another spac...

Hi, everyone. i am a new user of abinit. i had a problem to set up the rprim for AlLa (Cmcm #63 space group). i got the rprim and atomic coordinates from its prototype CrB.(see the nrl.navy website). but when i changed the acell for AlLa calculation, the out file give me another structure (#11space ...