<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Dear Peter and Respectful Wien Users,<div><br></div><div>1/</div><div>In the UG, page 147, I notice the following for the optical properties calculations ----</div><div><br></div><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">In cases of non-spinpolarized calculations WITHOUT inversion symmetry AND spin-orbit coupling,</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">one must do some tricks and “mimick” a spinpolarized calculation:</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I cp case.vsp case.vspup Line 1</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I cp case.vsp case.vspdn Line 2</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I cp case.vectorso case.vectorsoup Line 3</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I x lapw2 -fermi -so -c Line 4</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I cp case.weight case.weightup Line 5</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I cp case.weight case.weightdn Line 6</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I x optic -so -up Line 7</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I x joint -up Line 8</div></div><div><br></div><div>As I understand, the first sentence is saying that the case is non-spin polarized but has no "Inversion symmetry" and no "spin-orbit coupling". </div><div>Then in this case, how can the file "case.vectorso" (3rd line of the above tricks) is created now that the spin-orbit coupling does not exist? </div><div>However, from the lines 4 and 7, the "-so" switch is included, I suspect the case has the "spin-orbit coupling". </div><div><br></div><div>On the other hand, I also read the following paragraph</div><div><br></div><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">In order to get the correct matrix elements, the files <b>case.vectorso[up|dn] </b>have to be used.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">For that purpose the following procedure is recommended:</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I run SCF cycle: <b>run[sp] lapw -so</b></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I generate a fine k-mesh for the optics part: <b>x kgen [-so (if case.ksym has been</b></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; "><b>created by symmetso) ]</b></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I change TOT to FERMI in <b>case.in2c</b></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I execute <b>run[sp] lapw -so -s lapw1 -e lcore </b>with this fine k-mesh</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I run optic: <b>x opticc -so [-up]</b></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I run joint: <b>x joint [-up]</b></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Helvetica; ">I run kram: <b>x kram [-up]</b></div></div><div><br></div><div>It seems the immediately above procedure should also be applicable to the non-spin polarized case but with spin-orbit coupling. </div><div><br></div><div>I am confused here and very much appreciate a clarification. </div><div><br></div><div>2/ Another question: </div><div><br></div><div>Does the current "OPTICS" support the LDA+U?</div><div><br></div><div><br></div><div>Thanks,</div><div><br></div><div>Jianxin</div><div><br></div><div><br></div><div><br></div></body></html>