<div dir="ltr"><div class="gmail_default" style="font-family:garamond,serif;font-size:large">Dear J Morteza and Wien2k user<br><br></div><div class="gmail_default" style="font-family:garamond,serif;font-size:large">I have installed IR elastic (Cubic) for calculating the elastic constant of the Half Heusler alloy CoTiSb (can be written TiCoSb). The space group should be No 216 (F -43m) as Wien2k produces by sgroup. This is consistent with its structure. However, For calculating the elastic constant I noted that IR elast produces the space group No. 22 (F222) as shown below:<br>
---------------------------------------------------------------------------------------------------------------<br>Start for AUTO intialization Styp1__4.0 <br>##########################################<br> 3 Atoms found: Co Ti Sb <br>
generate atomic configuration for atom 1 : Co<br>generate atomic configuration for atom 2 : Ti<br>generate atomic configuration for atom 3 : Sb<br>next is setrmt<br> specify nn-bondlength factor: (usually=2) [and optionally dlimit, dstmax (about<br>
1.d-5, 20)]<br> DSTMAX: 20.0000000000000 <br> iix,iiy,iiz 4 4 4 42.6902880000000 <br> 44.5403160000000 46.2478120000000 <br> NAMED ATOM: Co1 Z changed to IATNR+999 to determine equivalency<br>
NAMED ATOM: Ti1 Z changed to IATNR+999 to determine equivalency<br> NAMED ATOM: Sb1 Z changed to IATNR+999 to determine equivalency<br><br> ATOM 1 Co1 ATOM 3 Sb1 <br> RMT( 1)=2.32000 AND RMT( 3)=2.32000<br>
SUMS TO 4.64000 LT. NN-DIST= 4.81905<br><br> ATOM 2 Ti1 ATOM 1 Co1 <br> RMT( 2)=2.26000 AND RMT( 1)=2.32000<br> SUMS TO 4.58000 LT. NN-DIST= 4.81905<br><br> ATOM 3 Sb1 ATOM 1 Co1 <br>
RMT( 3)=2.32000 AND RMT( 1)=2.32000<br> SUMS TO 4.64000 LT. NN-DIST= 4.81905<br>NN ENDS<br>0.000u 0.002s 0:00.01 0.0% 0+0k 24+48io 0pf+0w<br>> sgroup (20:47:13) 0.000u 0.000s 0:00.00 0.0% 0+0k 0+8io 0pf+0w<br>
Names of point group: 222 222 D2<br> Names of point group: 222 222 D2<br> Names of point group: 222 222 D2<br>Number and name of space group: 22 (F 2 2 2)<br>> symmetry (20:47:13) 0.000u 0.001s 0:00.01 0.0% 0+0k 16+32io 0pf+0w<br>
<br></div><div class="gmail_default" style="font-family:garamond,serif;font-size:large">I checked the the atomic positions and found nothing wrong. <br><br>Can you please tell us why the space group is F222 rather than F -43m.<br>
<br></div><div class="gmail_default" style="font-family:garamond,serif;font-size:large">Best regards<br><br></div><div class="gmail_default" style="font-family:garamond,serif;font-size:large">O A Yassin<br></div><div class="gmail_default" style="font-family:garamond,serif;font-size:large">
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