<p style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US"><font face="arial,sans-serif">Hello everyone,</font></span></p>
<div style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US"><font face="arial,sans-serif">When I calculated the dissociation energy of the ground state of a diatomic molecule BrCl, it is found that the calculated result (De= 2.163eV
) is lower than the experimental one (De=2.221eV). Our result was derived by fitting the PEC of the ground state using Le Roy's LEVEL program. From the difference between the minimum energy of the PEC of the ground state and the total energy of two isolated atoms worse
1.924eV was got.</font></span></div>
<div style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US"></span> </div>
<p style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US"><font face="arial,sans-serif">Similar result was got for the CrCu molecule. Fitting the PEC of the ground state using Le Roy's LEVEL program we got De=1.03eV , while the experimental De=
1.36eV. Also worse 0.86eV was got from the difference between the minimum energy of the PEC of the ground state and the total energy of two isolated atoms.</font></span></p>
<div style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US"><font face="arial,sans-serif">So is this an intrinsic problem of the theoretical method or a problem related to the calculated method that I selected? </font></span></div>
<div style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US">Thank you very much.</span></div>
<div style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US">Best regards,</span></div>
<div style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US">mingwei</span></div>
<div style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US"></span> </div>
<div style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US"><font face="arial,sans-serif">The following is our input file:</font></span></div>
<div style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US"><font face="arial,sans-serif">Brcl: </font></span></div>
<div style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US"></span><span lang="EN-US">***BrCl***<br> memory,90,m<br> gprint,orbital,basis<br> geometry={angstrom;<br> BR;<br> CL,BR,2.587;<br> }<br> basis={spdf,BR,cc-pVTZ-DK;c;
<br> s,BR,0.455930000E-01;<br> p,BR,0.351420000E-01;<br> d,BR,0.104700000E+00;<br> f,BR,0.258000000E+00;</span></div>
<div style="MARGIN: 0cm 0cm 0pt">
<p> spdf,CL,cc-pVTZ-DK;c;<br> s,CL,0.591000000E-01;<br> p,CL,0.419000000E-01;<br> d,CL,0.135000000E+0;<br> f,CL,0.312000000E+00;<br> }</p>
<p> dkroll=1;</p>
<p> hf;<br> occ,13,6,6,1;wf,52,1,0;</p>
<p> multi;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;<br> wf,52,1,0;state,3;wf,52,1,2;state,3;wf,52,2,0;state,2;wf,52,2,2;state,2;<br> wf,52,3,0;state,2;wf,52,3,2;state,2;wf,52,4,0;state,2;wf,52,4,2;state,3;</p>
<p> mrci;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;wf,52,1,0;<br> restrict,0,1,15.1;option,nstati=6;state,3;<br> mrci;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;wf,52,1,2;<br> restrict,0,1,15.1;option,nstati=6;state,3;<br>
<br> mrci;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;wf,52,2,0;<br> restrict,0,1,15.1;option,nstati=4;state,2;<br> <br> mrci;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;wf,52,2,2;<br> restrict,0,1,15.1;option,nstati=4;state,2;
<br> <br> mrci;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;wf,52,4,0;<br> restrict,0,1,15.1;option,nstati=4;state,2;<br> <br> mrci;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;wf,52,4,2;<br> restrict,0,1,15.1;option,nstati=6;state,3;
<br>--------------------------------</p>
<p>***BrCl***<br>memory,90,m<br>gprint,orbital,basis<br>geometry={angstrom;<br> BR;<br> CL,BR,2.587;<br> }<br>e_cisd(1) =-3065.65765713<br>e_cisd(2) =-3065.55955517<br>e_cisd(3) =-3065.55577986
<br>e_cisd(4) =-3065.60342217<br>e_cisd(5) =-3065.57629849<br>e_cisd(6) =-3065.60342217<br>e_cisd(7) =-3065.57629849<br>e_cisd(8) =-3065.55955517<br>e_cisd(9) =-3065.55231646<br>e_cisd(10)=-3065.56835310<br>e_cisd(11)=-3065.55071012
<br>e_cisd(12)=-3065.54922167<br>e_cisd(13)=-3065.61818535<br>e_cisd(14)=-3065.58110275<br>e_cisd(15)=-3065.61818535<br>e_cisd(16)=-3065.58110275<br>e_cisd(17)=-3065.56509009<br>e_cisd(18)=-3065.55071012<br>e_cisd(19)=-3065.44262005
</p>
<p>basis={spdf,BR,cc-pVTZ;<br> spdf,CL,cc-pVTZ;<br> }</p>
<p>hf;<br>occ,13,6,6,1;wf,52,1,0;</p>
<p>multi;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;<br>wf,52,1,0;state,3;wf,52,1,2;state,3;wf,52,2,0;state,2;wf,52,2,2;state,2;<br>wf,52,3,0;state,2;wf,52,3,2;state,2;wf,52,4,0;state,2;wf,52,4,2;state,3;</p>
<p>mrci;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;wf,52,1,0;<br>option,nstati=6;state,3;save,4010.1<br>noexc</p>
<p>mrci;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;wf,52,2,0;<br>option,nstati=4;state,2;save,4020.1<br>noexc</p>
<p>mrci;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;wf,52,3,0;<br>option,nstati=4;state,2;save,4030.1<br>noexc</p>
<p>mrci;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;wf,52,4,0;<br>option,nstati=4;state,2;save,4040.1<br>noexc</p>
<p>mrci;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;wf,52,1,2;<br>option,nstati=6;state,3;save,4012.1<br>noexc <br> <br>mrci;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;wf,52,2,2;<br>option,nstati=4;state,2;save,
4022.1<br>noexc<br> <br>mrci;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;wf,52,3,2;<br>option,nstati=4;state,2;save,4032.1<br>noexc<br> <br>mrci;occ,15,6,6,1;core,8,3,3;closed,10,4,4,1;wf,52,4,2;<br>option,nstati=6;state,3;save,
4042.1<br>noexc</p>
<p>lsint</p>
<p>hlsdiag=e_cisd;</p>
<p>mrci;hlsmat,ls,4010.1,4020.1,4030.1,4040.1,4012.1,4022.1,4032.1,4042.1;<br>print,HLS=2,VLS=0;</p>
<p>CrCu:</p>
<p>***CrCu<br>memory,250,m<br>gprint,orbital,basis<br>geometry={angstrom<br>Cr<br>Cu,Cr,2.468}</p>
<p>basis={spdf,Cr,Bauschlicher-ANO;c,<br>spdf,Cu,Bauschlicher-ANO;c}</p>
<p>dkroll=1<br>uhf<br>occ,16,6,6,2<br>closed,12,5,5,1<br>wf,53,1,7<br>maxiter,100<br>orbprint,10</p>
<p>multi<br>occ,16,6,6,2<br>core,10,4,4<br>wf,53,4,3;state,3</p>
<p>multi<br>occ,16,6,6,2<br>core,10,4,4;closed,10,5,5<br>wf,53,4,3;state,3</p>
<p>multi<br>occ,16,6,6,2<br>core,10,4,4;closed,10,4,4<br>wf,53,4,3;state,3</p>
<p>mrci<br>occ,16,6,6,2<br>core,10,4,4;closed,10,4,4<br>wf,53,1,5;<br>pspace,0.2<br>natorb,print<br>ed15=energd<br></p>
<p><br> </p></div>