<div dir="ltr">HI Marcella,<div><br></div><div>Thank you. Potential and basis set aside (I can fix that easily), I was under the impression that the ABC settings were indeed defining the supercell, which then, combined with PERIODIC XYZ would give me the desired setup overall. What are you suggesting instead?</div>
<div><br></div><div>Thanks,</div><div><br></div><div>Alex</div><div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Fri, Aug 15, 2014 at 3:05 PM, Marcella Iannuzzi <span dir="ltr"><<a href="mailto:marci...@gmail.com" target="_blank">marci...@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi<div><br></div><div>Just few remarks.</div><div><br></div><div>For the fcc bulk Ni energy, you need to construct a supercell, since there is no k-point sampling,</div>
<div>and check the convergence of the result with system size.</div><div><br></div><div>PADE is probably not an optimal choice for the XC functional, anyway, you should use consistent potential and basis set,</div><div>i.e. for the same number of valence electrons (in your input, the PP is for 10 v.e. and the BS for 18)</div>
<div><br></div><div>If you don't specify in in the input, no spin polarisation is considered.</div><div><br></div><div>Regards</div><span class="HOEnZb"><font color="#888888"><div><br></div><div>Marcella</div></font></span><div>
<div class="h5"><div> <br><br>On Friday, August 15, 2014 10:19:59 PM UTC+2, Alex wrote:<blockquote class="gmail_quote" style="margin:0;margin-left:0.8ex;border-left:1px #ccc solid;padding-left:1ex">Hi all,<div><br></div>
<div>I am very new to DFT calculations, let alone CP2k, so some level of idiocy on my part should be expected.</div><div>As a simple test, I am trying to calculate the binding energy of a Ni atom in a bulk crystal. The relevant portion of the input shown below:</div>
<div><br></div><div>***</div><div><div><font face="courier new, monospace">&GLOBAL</font></div><div><font face="courier new, monospace"> PROJECT Ni_inp_test</font></div><div><font face="courier new, monospace"> RUN_TYPE ENERGY_FORCE</font></div>
<div><font face="courier new, monospace"> PRINT_LEVEL LOW</font></div><div><font face="courier new, monospace">&END GLOBAL</font></div><div><font face="courier new, monospace">&FORCE_EVAL</font></div><div><font face="courier new, monospace"> METHOD Quickstep</font></div>
<div><font face="courier new, monospace"> &SUBSYS</font></div><div><font face="courier new, monospace"> &KIND Ni</font></div><div><font face="courier new, monospace"> ELEMENT<span style="white-space:pre-wrap"> </span>Ni</font></div>
<div><font face="courier new, monospace"> BASIS_SET DZV-GTH-PADE-q18</font></div><div><font face="courier new, monospace"> POTENTIAL GTH-PADE-q10</font></div><div><font face="courier new, monospace"> &END KIND</font></div>
<div><font face="courier new, monospace"> &CELL</font></div><div><font face="courier new, monospace"> A 1.765000 1.765000 0.000000</font></div><div><font face="courier new, monospace"> B 0.000000 1.765000 1.765000</font></div>
<div><font face="courier new, monospace"> C<span style="white-space:pre-wrap"> </span> 1.765000 0.000000 1.765000</font></div><div><font face="courier new, monospace"> PERIODIC<span style="white-space:pre-wrap"> </span>XYZ</font></div>
<div><font face="courier new, monospace"> &END CELL</font></div><div><font face="courier new, monospace"> &COORD</font></div><div><font face="courier new, monospace"> Ni 0.000000000 0.000000000 0.000000000</font></div>
<div><font face="courier new, monospace"> &END COORD</font></div><div><font face="courier new, monospace"> &END SUBSYS</font></div><div><font face="courier new, monospace"> &DFT</font></div><div><font face="courier new, monospace"> BASIS_SET_FILE_NAME BASIS_SET</font></div>
<div><font face="courier new, monospace"> POTENTIAL_FILE_NAME GTH_POTENTIALS</font></div><div><font face="courier new, monospace"> &QS</font></div><div><font face="courier new, monospace"> EPS_DEFAULT 1.0E-10</font></div>
<div><font face="courier new, monospace"> &END QS</font></div><div><font face="courier new, monospace"> &MGRID</font></div><div><font face="courier new, monospace"> NGRIDS 4</font></div><div><font face="courier new, monospace"> CUTOFF 300</font></div>
<div><font face="courier new, monospace"> REL_CUTOFF 60</font></div><div><font face="courier new, monospace"> &END MGRID</font></div><div><font face="courier new, monospace"> &XC</font></div><div><font face="courier new, monospace"> &XC_FUNCTIONAL PADE</font></div>
<div><font face="courier new, monospace"> &END XC_FUNCTIONAL</font></div><div><font face="courier new, monospace"> &END XC</font></div><div><font face="courier new, monospace"> &SCF</font></div><div>
<font face="courier new, monospace"> SCF_GUESS ATOMIC</font></div><div><font face="courier new, monospace"> EPS_SCF 1.0E-7</font></div><div><font face="courier new, monospace"> MAX_SCF 300</font></div><div>
<font face="courier new, monospace"> ADDED_MOS 10</font></div><div><font face="courier new, monospace"> &DIAGONALIZATION ON</font></div><div><font face="courier new, monospace"> ALGORITHM STANDARD</font></div>
<div><font face="courier new, monospace"> &END DIAGONALIZATION</font></div><div><font face="courier new, monospace"> &MIXING T</font></div><div><font face="courier new, monospace"> METHOD BROYDEN_MIXING</font></div>
<div><font face="courier new, monospace"> ALPHA 0.4</font></div><div><font face="courier new, monospace"> NBROYDEN 8</font></div><div><font face="courier new, monospace"> &END MIXING</font></div><div>
<font face="courier new, monospace"> &SMEAR ON</font></div><div><font face="courier new, monospace"> METHOD FERMI_DIRAC</font></div><div><font face="courier new, monospace"> ELECTRONIC_TEMPERATURE [K] 300</font></div>
<div><font face="courier new, monospace"> &END SMEAR</font></div><div><font face="courier new, monospace"> &END SCF</font></div><div><font face="courier new, monospace"> &END DFT</font></div><div><font face="courier new, monospace"> &PRINT</font></div>
<div><font face="courier new, monospace"> &FORCES ON</font></div><div><font face="courier new, monospace"> &END FORCES</font></div><div><font face="courier new, monospace"> &END PRINT</font></div><div><font face="courier new, monospace">&END FORCE_EVAL</font></div>
</div><div><font face="courier new, monospace"><br></font></div><div><font face="courier new, monospace">***</font></div><div><font face="courier new, monospace"><br></font></div><div><font face="courier new, monospace">This yields a total energy of E1=-35.155 a.u. after convergence.</font></div>
<div><font face="courier new, monospace"><br></font></div><div><font face="courier new, monospace">Then I decided to calculate the "vacuum" energy of an isolated atom, input below:</font></div><div><font face="courier new, monospace"><br>
</font></div><div><font face="courier new, monospace"><div>&GLOBAL</div><div> PROJECT Ni_inp_test</div><div> RUN_TYPE ENERGY_FORCE</div><div> PRINT_LEVEL LOW</div><div>&END GLOBAL</div><div>&FORCE_EVAL</div>
<div> METHOD Quickstep</div><div> &SUBSYS</div><div> &KIND Ni</div><div> ELEMENT<span style="white-space:pre-wrap"> </span>Ni</div><div> BASIS_SET DZV-GTH-PADE-q18</div><div> POTENTIAL GTH-PADE-q10</div>
<div> &END KIND</div><div> &CELL</div><div> A 30.00000 0.000000 0.000000</div><div> B 0.000000 30.00000 0.000000</div><div> C<span style="white-space:pre-wrap"> </span> 0.000000 0.000000 30.00000</div>
<div> &END CELL</div><div> &COORD</div><div> Ni 0.000000000 0.000000000 0.000000000</div><div> &END COORD</div><div> &END SUBSYS</div><div> &DFT</div><div> BASIS_SET_FILE_NAME BASIS_SET</div>
<div> POTENTIAL_FILE_NAME GTH_POTENTIALS</div><div> &QS</div><div> EPS_DEFAULT 1.0E-10</div><div> &END QS</div><div> &MGRID</div><div> NGRIDS 4</div><div> CUTOFF 300</div><div> REL_CUTOFF 60</div>
<div> &END MGRID</div><div> &XC</div><div> &XC_FUNCTIONAL PADE</div><div> &END XC_FUNCTIONAL</div><div> &END XC</div><div> &SCF</div><div> SCF_GUESS ATOMIC</div><div> EPS_SCF 1.0E-7</div>
<div> MAX_SCF 300</div><div> ADDED_MOS 10</div><div> &DIAGONALIZATION ON</div><div> ALGORITHM STANDARD</div><div> &END DIAGONALIZATION</div><div> &MIXING T</div><div> METHOD BROYDEN_MIXING</div>
<div> ALPHA 0.4</div><div> NBROYDEN 8</div><div> &END MIXING</div><div> &SMEAR ON</div><div> METHOD FERMI_DIRAC</div><div> ELECTRONIC_TEMPERATURE [K] 300</div><div> &END SMEAR</div>
<div> &END SCF</div><div> &END DFT</div><div> &PRINT</div><div> &FORCES ON</div><div> &END FORCES</div><div> &END PRINT</div><div>&END FORCE_EVAL</div><div><br></div><div>***</div><div>
<br></div><div>This also converges and yields a total energy E2=-34.555 a.u.</div><div><br></div><div><br></div><div>Hence, my questions:</div><div><br></div><div>1. Is this even the correct way of calculating what I want, including the energy calculations, XC functional, and basis?</div>
<div>2. Should the spin properties be explicitly set in the input? There are none now.</div><div>3. Am I setting up the FCC lattice correctly (first input file)? My translation vectors are set by the ABC values, but I have no idea whether this is right.</div>
<div>4. If the first simulation yields the total energy of the system and the FCC lattice implies 12 nearest neighbors, then removing the center would change the total energy by (E1-E2)/6, which isn't the experimental -4.4 eV. Am I completely off track here? :)</div>
<div><br></div><div>Thanks a lot!</div></font></div></blockquote></div></div></div></div><div class="HOEnZb"><div class="h5">
<p></p>
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