<div dir="ltr">Dear Wien2K community,<br><div>            I am currently using the latest version of the WIEN2k package (<b>Version: WIEN2k_23.2</b>). I am calculating the <b>momentum matrix elements</b> using the OPTIC module as implemented in the WIEN2k package. From userguide I found that the momentum matrix elements will be written in <b><i>case.mommat2</i></b> file. </div><div>            I am performing SOC included calculations on TaAs using the <b><i>PBESol</i></b> as an exchange correlation functional. My <b>TaAs.inop</b> file looks like:</div><div><br></div><div>99999 1    number of k-points, first k-point<br>-0.5 0.5 9999 Emin, Emax for matrix elements, NBvalMAX<br>2       number of choices (columns in *outmat): 2: hex or tetrag. case<br>1       Re xx<br>3       Re zz<br>ON       ON/OFF  writes MME to unit 4<br>1<br></div><div><br></div><div>I have observed that <b>once the scf converged ground state is obtained</b>, there is <b>no change in the momentum matrix elements values </b>(in TaAs.mommat2 file) <b>if we repeat the calculations</b> of TaAs.mommat2 file. <b>However, if I rerun the scf calculations again from starting and then obtain the TaAs.mommat2 file, the data in the file gets changed (considerable changes are observed).</b> Note: All the parameters during these two calculations are kept the same. I am showing below the output file (TaAs.mommat2 file) obtained during the two calculations.</div><div><br></div><div><b>First calculation:</b></div><div> </div><div>  Complex momentum matrix elements: (Re_x,Im_x),(Re_y,Im_y),(Re_z,Im_z)<br><br>  KP:   1 NEMIN NEMAX :   65  70 dE:  -0.5  0.5 K:     1<br><br> 65  65 -6.791572E-14  4.326127E-16 -1.908323E-12 -6.827043E-12 -1.230687E-12  4.691060E-07   0.00000000<br> 65  66  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00   0.00000000<br> 65  67 -1.122490E-04  1.272331E-04  7.983179E-05 -3.217857E-05  4.305635E-11 -9.848311E-12   0.17874679<br> 65  68  1.660215E-03  5.409568E-04  5.499541E-04 -1.663694E-03  2.075423E-12  3.826721E-12   0.17874679<br> 65  69  3.936429E-04  1.240500E-03  1.266557E-03 -3.814258E-04  3.255843E-13  4.740868E-12   0.51386663<br> 65  70 -1.237442E-04 -3.543114E-04 -2.453771E-04  1.574218E-04  4.178337E-12  6.320158E-12   0.51386663<br> 66  66 -6.791572E-14  4.326127E-16 -1.908323E-12 -6.827043E-12 -1.230687E-12  4.691060E-07   0.00000000<br> 66  67  1.660215E-03  5.409568E-04  5.499541E-04 -1.663694E-03  2.075423E-12  3.826721E-12   0.17874679<br> 66  68 -1.122490E-04  1.272331E-04  7.983179E-05 -3.217857E-05  4.305635E-11 -9.848311E-12   0.17874679<br> 66  69 -1.237442E-04 -3.543114E-04 -2.453771E-04  1.574218E-04  4.178337E-12  6.320158E-12   0.51386663<br> 66  70  3.936429E-04  1.240500E-03  1.266557E-03 -3.814258E-04  3.255843E-13  4.740868E-12   0.51386663<br> 67  67 -3.062120E-11 -1.361805E-15 -1.900231E-11 -1.083939E-11 -1.835530E-10 -1.298187E-05   0.00000000<br> 67  68  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00   0.00000000<br> 67  69  8.836885E-03 -5.639363E-03  5.375814E-03  8.636869E-03  4.880596E-02  1.287101E-01   0.33511984<br> 67  70 -1.671701E-03  1.109599E-03 -2.253235E-03 -2.312311E-03  1.325112E-01  4.650952E-01   0.33511984<br> 68  68 -3.062120E-11 -1.361805E-15 -1.900231E-11 -1.083939E-11 -1.835530E-10 -1.298187E-05   0.00000000<br> 68  69 -1.671701E-03  1.109599E-03 -2.253235E-03 -2.312311E-03  1.325112E-01  4.650952E-01   0.33511984<br> 68  70  8.836885E-03 -5.639363E-03  5.375814E-03  8.636869E-03  4.880596E-02  1.287101E-01   0.33511984<br> 69  69 -7.367419E-12  1.678033E-15 -1.891869E-11  1.300217E-12 -4.739680E-11  1.787176E-05   0.00000000<br> 69  70  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00   0.00000000<br> 70  70 -7.367419E-12  1.678033E-15 -1.891869E-11  1.300217E-12 -4.739680E-11  1.787176E-05   0.00000000<br><br>  KP:   2 NEMIN NEMAX :   65  72 dE:  -0.5  0.5 K:     2<br><br> 65  65  9.561577E-02  6.302006E-07  9.561578E-02 -6.302075E-07 -3.861626E-10  7.639556E-07   0.00000000<br> 65  66  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00   0.00030716<br> 65  67 -1.500039E-03  1.544209E-03 -1.500158E-03 -1.544114E-03  4.595806E-09  5.467578E-04   0.16416515<br> 65  68 -1.734816E-03 -2.038025E-03 -1.734780E-03  2.038026E-03  2.598629E-08  1.625489E-04   0.17013061<br></div><div><br></div><div><b>Second calculation:</b></div><div><br></div><div>  Complex momentum matrix elements: (Re_x,Im_x),(Re_y,Im_y),(Re_z,Im_z)<br><br>  KP:   1 NEMIN NEMAX :   65  70 dE:  -0.5  0.5 K:     1<br><br> 65  65 -7.845272E-12  5.460652E-17  6.845644E-13 -6.827471E-12 -3.414512E-12  4.691060E-07   0.00000000<br> 65  66  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00   0.00000000<br> 65  67 -3.691215E-04  1.629442E-03  1.510884E-03  3.903687E-04 -2.048646E-11 -2.391975E-12   0.17874679<br> 65  68 -1.935785E-04 -5.696257E-04  8.347352E-04 -1.460673E-04  3.717129E-11 -1.078993E-11   0.17874679<br> 65  69  1.272132E-04 -1.157650E-03 -4.132527E-04 -3.733865E-04 -1.266540E-12  4.856729E-13   0.51386663<br> 65  70  3.871718E-04 -4.810268E-04 -1.183538E-03 -1.633025E-04  1.166324E-12 -1.468572E-12   0.51386663<br> 66  66 -7.845272E-12  5.460652E-17  6.845644E-13 -6.827471E-12 -3.414512E-12  4.691060E-07   0.00000000<br> 66  67 -1.935785E-04 -5.696257E-04  8.347352E-04 -1.460673E-04  3.717129E-11 -1.078993E-11   0.17874679<br> 66  68 -3.691215E-04  1.629442E-03  1.510884E-03  3.903687E-04 -2.048646E-11 -2.391975E-12   0.17874679<br> 66  69  3.871718E-04 -4.810268E-04 -1.183538E-03 -1.633025E-04  1.166324E-12 -1.468572E-12   0.51386663<br> 66  70  1.272132E-04 -1.157650E-03 -4.132527E-04 -3.733865E-04 -1.266540E-12  4.856729E-13   0.51386663<br> 67  67 -6.209961E-11 -5.437752E-15  7.061251E-11 -1.084517E-11 -1.171486E-10 -1.298187E-05   0.00000000<br> 67  68  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00   0.00000000<br> 67  69 -5.944409E-03 -1.682884E-03 -1.372490E-03  6.934560E-03 -3.516587E-01 -1.020410E-01   0.33511984<br> 67  70  6.567929E-03  1.343172E-03  1.661758E-03 -5.511497E-03 -3.165542E-01 -1.362602E-01   0.33511984<br> 68  68 -6.209961E-11 -5.437752E-15  7.061251E-11 -1.084517E-11 -1.171486E-10 -1.298187E-05   0.00000000<br> 68  69  6.567929E-03  1.343172E-03  1.661758E-03 -5.511497E-03 -3.165542E-01 -1.362602E-01   0.33511984<br> 68  70 -5.944409E-03 -1.682884E-03 -1.372490E-03  6.934560E-03 -3.516587E-01 -1.020410E-01   0.33511984<br> 69  69  2.024387E-11  5.052165E-15  2.031190E-11  1.307417E-12 -2.125244E-11  1.787176E-05   0.00000000<br> 69  70  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00   0.00000000<br> 70  70  2.024387E-11  5.052165E-15  2.031190E-11  1.307417E-12 -2.125244E-11  1.787176E-05   0.00000000<br><br>  KP:   2 NEMIN NEMAX :   65  72 dE:  -0.5  0.5 K:     2<br><br> 65  65  9.561577E-02  6.302003E-07  9.561577E-02 -6.302073E-07 -4.163895E-10  7.639556E-07   0.00000000<br> 65  66  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00   0.00030716<br> 65  67  1.500038E-03 -1.544209E-03  1.500158E-03  1.544114E-03 -5.230746E-09 -5.467574E-04   0.16416515<br> 65  68 -1.734810E-03 -2.038025E-03 -1.734786E-03  2.038025E-03  2.622505E-08  1.625494E-04   0.17013061<br></div><div><br></div><div>I am observing that almost all the values are getting changed. So, if I am using these values to calculate some transport, I am getting different result each time (<b>I have verified it</b>). Please guide me regarding what is going on here. <b>Also, how can I get the correct values of momentum matrix so that I can get reliable results upon using them in some other calculation.</b></div><div><br></div><div><b>Thanks and Regards</b><br><br><b>Yours Sincerely</b><font color="#888888"><font color="#888888"><font color="#888888"><br>Vivek Pandey<br>Research Scholar<br>Indian Institute of Technology, Mandi<br></font><div>Himachal Pradesh, India </div></font></font></div></div>