<HTML><BODY><br><br>
Dear molpro community,<br><br>May be someone could help me with the obtaining of C8_000 dispesion coefficient from EOM-CCSD calculations?<br><br><br>Here is an example for N2-N2:<br><br>Uning proparator methof of Tatiana Corona we obtain <X;Y>:<br>a6633 := 136.6805842; <br>a4433 := 78.70125049; <br>a5533 := 78.70125049; <br>a5633 := -68.34029205;<br>a4633 := -68.34029205; <br>a4533 := -10.36095844; <br>a8833 := 97.21710728; <br>a8811 := 70.14620802; <br>a4411 := 57.06216406;<br>a5511 := 57.06216406; <br>a4511 := -7.578876794; <br>a6611 := 98.96657460; <br>a5611 := -49.48328727;<br>a4611 := -49.48328727;<br>as i understand, a6633=<zz,zz;zz> (for example). <br>here <br>1 - x<br>2 - y<br>3 - z<br>4 - xx<br>5 - yy<br>6 - zz<br>7 - xy<br>8 - xz<br>9 - yz<br>...<br><br><br>after, we have an expression for X integrals: <br>X2100=1/4(4*a6633+a4433+a5533-4*a5633-4*a4633+2*a4533)<br>X2101 ....<br><br>But when I use the formula for C8 isotropic coefficient, I have not obtained correct results (I obtain 4775 instead of correct value around 2500). <br>C000_8=X2100+2*X2101+2*X2110+4*X2111+2*X2120+4*X2121+X1200+2*X1201+2*X1210+4*X1211+2*X1202+4*X1212<br>(Ref. J Comput Chem 32: 279–290, 2011 : "Long-Range Interaction for Dimers of Atmospheric Interest: Dispersion, Induction and Electrostatic Contributions for O2–O2, N2–N2 and O2–N2")<br><br>May be someone can indicate where is a mistake. For C6 coefficients I have no problems. <br><br>I would be very appreciated any help. <br><br>Best regards, <br><br><font face="Arial, Helvetica">Yulia KALUGINA <br> LOMC - Université du Havre <br> 25 Rue Philippe Lebon <br> BP 540 - 76 058 Le Havre cedex FRANCE <br> tel: <span class="js-phone-number">+33 (0)2 35 21 71 03 </span><br> --------- <br> OS - Tomsk State University <br> 36, Lenina av. 634050 Tomsk RUSSIE <br> Mail : yulia.kalugina@univ-lehavre.fr , kalugina@phys.tsu.ru </font><br><br>
<br><hr>
<br>ICQ Number: 429-874-882<br></BODY></HTML>