<meta http-equiv="Content-Type" content="text/html; charset=utf-8"><div dir="ltr">I would like to ensure that I understand what the "-du" option (up/dn-crossterm) is; I could not find a clear explanation in the UG or via the mailing list.<div><br></div><div>My guess is that with, for instance, -orb the "-up" part is modelling the exchange term -<U_a(1)|<U_b(2)|1/r_12|U_b(1)>|U_a(2)> whereas the "-du" term would be +<U_a(1)|<D_b(2)|1/r_12|D_b(1)>|U_a(2)>. This might be wrong.</div><div><br></div><div>N.B., assuming lapwso is used for orb etc.</div><div><br></div><div>N.N.B., unfortunately a google search is not that useful, e.g. <a href="https://books.google.com/books?id=60MeAwAAQBAJ&pg=PA172&lpg=PA172&dq=up/dn+crossterm&source=bl&ots=1XzbWP8bTN&sig=4UOxnDw9eZnctouSYT5aSCHhAAs&hl=en&sa=X&ved=0ahUKEwjmmqehvtLMAhVn4YMKHYjADUkQ6AEILzAD#v=onepage&q=up%2Fdn%20crossterm&f=false">https://books.google.com/books?id=60MeAwAAQBAJ&pg=PA172&lpg=PA172&dq=up/dn+crossterm&source=bl&ots=1XzbWP8bTN&sig=4UOxnDw9eZnctouSYT5aSCHhAAs&hl=en&sa=X&ved=0ahUKEwjmmqehvtLMAhVn4YMKHYjADUkQ6AEILzAD#v=onepage&q=up%2Fdn%20crossterm&f=false</a><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><span style="font-size:12.8px">Professor Laurence Marks</span><br></div><div dir="ltr"><span style="font-size:12.8px">"Research is to see what everybody else has seen, and to think what nobody else has thought", </span><span style="font-size:12.8px">Albert Szent-Gyorgi</span><br><a href="http://www.numis.northwestern.edu" target="_blank">www.numis.northwestern.edu</a> ; <span style="font-size:12.8px">Corrosion in 4D: </span><a href="http://MURI4D.numis.northwestern.edu" style="font-size:12.8px" target="_blank">MURI4D.numis.northwestern.edu</a><div><span style="font-size:12.8px">Partner of the CFW 100% program for gender equity, </span><a href="http://www.cfw.org/100-percent" style="font-size:12.8px" target="_blank">www.cfw.org/100-percent</a></div><div>Co-Editor, Acta Cryst A</div></div></div></div></div></div></div></div></div></div></div>
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