<div dir="ltr">Dear wien2k users,<div><br></div><div> We are doing a simulation study of a spinel ferrite having 56 atoms/cell. This ferrite exhibit non-colinear magnetism. However, as a first approximation we have simulated it in usual version of wien2k with colinear magnetism.</div>
<div><br></div><div>Our study showed, that even without structural optimization calculated Li extraction voltage (obtained from change in total energy due to Li extraction) matches very well with experimental value.</div>
<div><br></div><div>We have done the above calculation with GGA+U approach and it has run without any trouble.</div><div><br></div><div>However, for further accuracy we have first optimize its lattice parameters and then atomic coordinates. Optimization of atomic coordinates showed significant changes in the structure. That optimized structure was further used for voltage and DOS calculation with same GGA+U approach.</div>
<div><br></div><div>This time, after few iterations it showed,</div><div><br></div><div>error in vorb....uporb.def failed (we are using same U value here also as was done earlier)</div><div><br></div><div>Do you think that this error might be correlleted with wrong structural model or is associated with some other technical problem?</div>
<div><br></div><div>Of course we are simulating a non collinear magnetic syetem in a collinear code, but it has run smoothly before structural optimization and has given very accurate Li extraction voltage. </div><div><br>
</div><div>So, it may happen that structural optimization without considering non-colinear magnetism may have eventually has led to a "very wrong" structure...which is even further away than the actual one. Is it? <br clear="all">
<div><br></div><div>Looking forward to your valuable suggestions.</div><div><br></div><div>with regards,</div>-- <br>Shamik Chakrabarti<br>Senior Research Fellow<br>Dept. of Physics & Meteorology<br>Material Processing & Solid State Ionics Lab<br>
IIT Kharagpur<br>Kharagpur 721302<br>INDIA
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