<P>Dear all,</P>
<P>I try to understand how the atomic coordinates in crystallographic system are transformed into the orthogonal system by WIEN2k. </P>
<P>I am wondering if the atomic coordinates are transformed by WIEN2k using the following equations:</P>
<DIV><FONT size="2" face="Arial">In the general case with angles that can be different from 90 degrees:</FONT></DIV>
<DIV><FONT size="2" face="Arial">- the a-axis is depicted on the x-axis.</FONT></DIV>
<DIV><FONT size="2" face="Arial">- The b-axis lies in the xy-plane (with the angle gamma between the a- and b-axis).</FONT></DIV>
<DIV><FONT size="2" face="Arial">- The c-axis points towards you.</FONT></DIV>
<DIV><FONT size="2" face="Arial"></FONT> </DIV>
<DIV><FONT size="2" face="Arial">So x-coordinate is easy to calculate, the z-coordinate is complicated!</FONT></DIV>
<DIV><FONT size="2" face="Arial"></FONT> </DIV>
<DIV><FONT size="2" face="Arial">Here in total: (x1,y,1,z1) is crystal coordinates, (x2,y2,z2) is orthogonal coordinates.</FONT></DIV>
<DIV><FONT size="2" face="Arial"></FONT> </DIV>
<DIV><FONT size="2" face="Arial">x2 = x1 * a</FONT></DIV>
<DIV><FONT size="2" face="Arial"></FONT> </DIV>
<DIV><FONT size="2" face="Arial">y2 = x1 * b * cos(gamma) + y1 * b * sin(gamma) [when gamma == 90 deg -> y2 = y1 * b]</FONT></DIV>
<DIV><FONT size="2" face="Arial"></FONT> </DIV>
<DIV><FONT size="2" face="Arial">z2 = x1 * c * cos(beta) + y1 * c * P + z1 * c * Q</FONT></DIV>
<DIV><FONT size="2" face="Arial"></FONT> </DIV>
<DIV><FONT size="2" face="Arial">with: P = (cos(alpha) - cos(beta) * cos(gamma)) / sin(gamma)</FONT></DIV>
<DIV><FONT size="2" face="Arial">and: Q = sqrt(sin^2(beta) - P^2)</FONT></DIV>
<P>Thank you in advance!</P>
<P>Best wishes,</P>
<P>Bing<BR></P><br><br><br>