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Dear Quantum Espresso users,</div>
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I calculated Raman tensor for two molecules with C<sub>2</sub> and C<sub>s</sub> point group symmetry. Below is a snippet of the Raman tensor:</div>
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C<sub>2</sub></div>
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Raman tensor for mode B</div>
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0.000016 -0.019918 -0.000002</div>
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-0.019918 0.000042 0.038907</div>
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-0.000002 0.038907 0.000008</div>
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Raman tensor for mode A</div>
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-0.062958 -0.000018 0.003571</div>
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-0.000018 -0.139741 0.000016</div>
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0.003571 0.000016 -0.028091</div>
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C<sub>s</sub></div>
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Raman tensor for mode A"</div>
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0.000000 -0.000000 -0.000091</div>
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-0.000000 0.000000 0.000048</div>
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-0.000091 0.000048 0.000000</div>
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Raman tensor for mode A'</div>
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0.005167 -0.001406 0.000000</div>
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-0.001406 0.007422 0.000000</div>
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0.000000 0.000000 0.000776</div>
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I checked the literature and it seems that the Raman tensors for C<sub>2</sub> and C<sub>s</sub> should have the same generic form(for example, mode B from C<sub>2
</sub>should have the same form as A" from C<sub>s</sub>). But from my output above, they have different forms. Is it just because the basis vectors are different in these two symmetries? </div>
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PS: In C<sub>2 </sub>mode B, element (row, column) 11,13, 22, 31, 33 are supposed to be 0 but they are not quite 0. Same for mode A element 12, 21, 23, 32. What would be reason causing these elements to have small values?</div>
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Thanks,</div>
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Weilun Tang</div>
<pre class="elementToProof"><div class="elementToProof" style="white-space: normal; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: black;">Department of Materials Science and Engineering</div><div class="elementToProof" style="white-space: normal; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: black;">Iowa State University </div></pre>
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