<html><head></head><body><div class="yahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div dir="ltr" data-setdir="false"><div><div dir="ltr" data-setdir="false">Dear users:</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">I am going to calculate do phonon calculation and Raman spectra calculation of 2D perovskite (only at Gamma point), </div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">My procedure is like this: doint: vc-relax & scf→phonon calculation→dynmat</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">1.Should I put <span>assume_isolated='2D' in my <span><span style="color: rgb(0, 0, 0); font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;">vc-relax & scf input?</span></span></span></div><div dir="ltr" data-setdir="false">Ref: <span>q-e/PHonon/examples/example17/reference</span></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">Cause I'm not quite sure what is it mean here.</div><div dir="ltr" data-setdir="false"> <span>The extension of DFPT to two dimensional crystals, in "particular gated two-dimensional heterostructure", </span><br></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">Ref: <a href="https://www.quantum-espresso.org/wp-content/uploads/2022/03/ph_user_guide.pdf" rel="nofollow" target="_blank">https://www.quantum-espresso.org/wp-content/uploads/2022/03/ph_user_guide.pdf</a></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">Below is my vc-relax input example.</div><div dir="ltr" data-setdir="false"><br></div><div>&control</div><div dir="ltr" data-setdir="false"> calculation = 'vc-relax'</div><div> restart_mode='from_scratch'</div><div dir="ltr" data-setdir="false"> prefix ='2D_perovskite' !test100tri</div><div dir="ltr" data-setdir="false"> pseudo_dir = " <span><span style="color: rgb(0, 0, 0); font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;">pseudo_dir</span></span>"</div><div dir="ltr" data-setdir="false"> outdir=" <span><span style="color: rgb(0, 0, 0); font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;">outdir</span></span>"</div><div>/</div><div>&system</div><div> ibrav=14, !triclinic</div><div> celldm(1)=16.13770350000000,celldm(2)=0.99156550541343,celldm(3)=1.87963300392941,celldm(4)=-1.94983007225937e-03,celldm(5)=0.13312393987385,celldm(6)=5.68819706737211e-04</div><div> nat=94, ntyp=5,</div><div> ecutwfc=150</div><div> ecutrho=600</div><div> vdw_corr=grimme-d2</div><div>/</div><div>&electrons</div><div> conv_thr=1e-14</div><div>/</div><div>ATOMIC_SPECIES</div><div>Sn 118.71000 Sn_ONCV_PBE-1.2.upf</div><div>H 1.00784 H_ONCV_PBE-1.2.upf</div><div>C 12.011 C_ONCV_PBE-1.2.upf</div><div>I 126.90447 I_ONCV_PBE-1.2.upf</div><div>N 14.0067 N_ONCV_PBE-1.2.upf</div><div>ATOMIC_POSITIONS (crystal)</div><div>I 0.8103731347 0.6896489973 0.4992596099</div><div>I 0.1896268653 0.3103510028 0.5007403901</div><div>...</div><div><br></div><div>K_POINTS (automatic)</div><div> 5 5 1 1 1 1</div><div><br></div><div><br></div><div><br></div><div dir="ltr" data-setdir="false">Sincerely,</div><div><br></div><div dir="ltr" data-setdir="false"><span>National Yang Ming Chiao Tung University</span><br></div><div dir="ltr" data-setdir="false">HY Lu</div><div><br></div></div><br></div></div></body></html>