<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman, new york, times, serif;font-size:14pt"><DIV>Dear Wannier Users,</DIV>
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<DIV>In an attempt to generate the Wannier functions of the Cmc21 phase of hydrogen at 100GPa (already published in PRB 62, 15505, 2000), I relaxed the structure (with ABINIT) using LDA psp with a cut off energy of 60Ha and a 11x11x11 k-grid (convergence tests were done). The unit cell parameters are:</DIV>
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<DIV>acell (Bohr) 3.5802517040E+00 3.5802517040E+00 5.6948406845E+00<BR></DIV>
<DIV>rprim 4.9609471480E-01 8.6826841123E-01 0.0000000000E+00<BR> -4.9609471480E-01 8.6826841123E-01 0.0000000000E+00<BR> 0.0000000000E+00 0.0000000000E+00 1.0000000000E+00<BR></DIV>
<DIV>xred (reduced coordinates)<BR>2.5121514893E-01 2.5121514893E-01 5.7250684394E-01<BR>8.5213973344E-02 8.5213973344E-02 4.2749315606E-01<BR>7.4878485107E-01 7.4878485107E-01 7.2506843938E-02<BR>9.1478602666E-01 9.1478602666E-01 9.2749315606E-01</DIV>
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<DIV>The structure is insulating with Fermi level at 2.83eV. With 4 atoms in the primitive cell, two bands are fully occupied. My wannier90.win is:</DIV>
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<DIV>num_wann 2 !(since two bands are occupied)<BR>dis_win_max 3.5 !(only the two occupied states are in this window)<BR>num_iter 10000<BR>dis_num_iter 10000<BR>dis_conv_tol 1.0E-10<BR>iprint 1<BR>wannier_plot =true<BR>wannier_plot_format=xcrysden<BR>wannier_plot_supercell=3<BR>Begin Projections ! (Using two of the atoms as starting point)<BR>random<BR>f= 8.5213973344E-02, 8.5213973344E-02, 4.2749315606E-01 : l=0<BR>f= 7.4878485107E-01, 7.4878485107E-01, 7.2506843938E-02 : l=0<BR>End Projections<BR></DIV>
<DIV>However, after 10,000 iterations, I get the following in the output:</DIV>
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<DIV> Cycle: 10000<BR> WF centre and spread 1 ( -0.118897, -0.090041, 0.151445 ) 17.92856764<BR> WF centre and spread 2 ( -0.023007, -0.110858, 0.105187 ) 19.60921540<BR> Sum of centres and spreads ( -0.141904, -0.200898, 0.256632 ) 37.53778304</DIV>
<DIV> 10000 0.102E+00 4.0933874374 37.5377830446 432.59 <-- CONV<BR> O_D= 21.7668345 O_OD= 14.1241376 O_TOT= 37.5377830 <-- SPRD<BR> Delta: O_D= 0.1058381E+00 O_OD= -0.4324867E-02 O_TOT= 0.1015132E+00 <-- DLTA<BR> ------------------------------------------------------------------------------</DIV>
<DIV> Writing checkpoint file wannier90.chk... done</DIV>
<DIV> Final State<BR> WF centre and spread 1 ( -0.118897, -0.090041, 0.151445 ) 17.92856764<BR> WF centre and spread 2 ( -0.023007, -0.110858, 0.105187 ) 19.60921540<BR> Sum of centres and spreads ( -0.141904, -0.200898, 0.256632 ) 37.53778304</DIV>
<DIV> Spreads (Ang^2) Omega I = 1.646810960<BR> =============== Omega D = 21.766834519<BR> Omega OD = 14.124137566<BR> Final Spread (Ang^2) Omega Total = 37.537783045<BR></DIV>
<DIV> Wannier Function Num: 1 Maximum Im/Re Ratio = 18.718258<BR> Wannier Function Num: 2 Maximum Im/Re Ratio = 51.325554<BR></DIV>
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<DIV>The two Wannier functions are not real and the spread is large. Is this output reasonable or am I missing something? Is there a way to lower the spread and make the functions real?</DIV>
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<DIV>I'd appreciate your input.</DIV>
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<DIV>Regards,</DIV>
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<DIV>Vahid Askarpour</DIV>
<DIV>Physics Department</DIV>
<DIV>Dalhousie University</DIV>
<DIV>Halifax, Nova Scotia</DIV>
<DIV>Canada</DIV>
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