<HTML><BODY>Dear molpro users.<br>We calculate ab initio potentials of alkali metal - inert gase weakly bound molecules.<br>Our research group uses def2-asvp,atzvp,aqzvp basis sets for extrapolation to a complete basis set limit (2 and 3 point formulae from molpro manual-Lx,LHx,Ex2) .<br>But we stress, that these basis sets are not suitable for a 3-point extrapolation at all, because the lmax is the same for asvp and atzvp basis sets for Rb and Cs atoms:<br><span style="text-decoration: underline;">For Cs</span>:<br>def2-asvp<br>Library entry Cs ECP ECP46MDF selected for group 1<br> Library entry CS S def2-SVP selected for orbital group 1<br> Even tempered Cs S diffuse selected for group 1 nprim= 1 centre= 0.005 ratio= 2.271 dratio= 1.000<br> Library entry CS P def2-SVP selected for orbital group 1<br> Even tempered Cs P diffuse selected for group 1 nprim= 1 centre= 0.003 ratio= 5.198 dratio= 1.000<br> <span style="text-decoration: underline;">Library entry CS D def2-SVP </span> selected for orbital group 1<br> Even tempered Cs D diffuse selected for group 1 nprim= 1 centre= 0.008 ratio= 4.004 dratio= 1.000<br><br>def2-atzvp<br>Library entry Cs ECP ECP46MDF selected for group 1<br> Library entry CS S def2-TZVP selected for orbital group 1<br> Even tempered Cs S diffuse selected for group 1 nprim= 1 centre= 0.005 ratio= 2.271 dratio= 1.000<br> Library entry CS P def2-TZVP selected for orbital group 1<br> Even tempered Cs P diffuse selected for group 1 nprim= 1 centre= 0.003 ratio= 5.198 dratio= 1.000<br> <span style="text-decoration: underline;">Library entry CS D def2-TZVP</span> selected for orbital group 1<br> Even tempered Cs D diffuse selected for group 1 nprim= 1 centre= 0.004 ratio= 3.904 dratio= 1.000<br><br><span style="text-decoration: underline;">For Rb:</span><br>def2-asvp<br> Library entry Rb ECP ECP28MDF selected for group 2<br> Library entry RB S def2-SVP selected for orbital group 2<br> Even tempered Rb S diffuse selected for group 2 nprim= 1 centre= 0.006 ratio= 2.320 dratio= 1.000<br> Library entry RB P def2-SVP selected for orbital group 2<br> Even tempered Rb P diffuse selected for group 2 nprim= 1 centre= 0.003 ratio= 6.503 dratio= 1.000<br> <span style="text-decoration: underline;">Library entry RB D def2-SVP</span> selected for orbital group 2<br> Even tempered Rb D diffuse selected for group 2 nprim= 1 centre= 0.003 ratio= 8.238 dratio= 1.000<br><br>def2-atzvp<br> Library entry Rb ECP ECP28MDF selected for group 1<br> Library entry RB S def2-TZVP selected for orbital group 1<br> Even tempered Rb S diffuse selected for group 1 nprim= 1 centre= 0.006 ratio= 2.287 dratio= 1.000<br> Library entry RB P def2-TZVP selected for orbital group 1<br> Even tempered Rb P diffuse selected for group 1 nprim= 1 centre= 0.006 ratio= 2.500 dratio= 1.000<br> <span style="text-decoration: underline;">Library entry RB D def2-TZVP </span> selected for orbital group 1<br> Even tempered Rb D diffuse selected for group 1 nprim= 1 centre= 0.003 ratio= 3.569 dratio= 1.000<br><br>So, a 3-point extrapolation is forbidden here, because we need at least 3 basis sets with different lmax (unfortunately, we have only two: atzvp,aqzvp).<br>--------------------------------------------------------------------------------------------------------------------------------------<br>Besides that, extrapolation formulae depend on the cardinal number n (which is the part of the basis set name - i.e. 2 for asvp, 3 for atzvp, 4 for aqzvp, and <span style="text-decoration: underline;">should be equal to the lmax</span>). When we looked through output file, we noticed, that the same basis set has different lmax for different atoms:<br><br>For Cs (def2-aqzvp basis set with ecp46mdf)<br><br> Library entry Cs ECP ECP46MDF selected for group 2<br> Library entry AR S def2-QZVP selected for orbital group 1<br> Even tempered Ar S diffuse selected for group 1 nprim= 1 centre= 0.068 ratio= 2.441 dratio= 1.000<br> Library entry AR P def2-QZVP selected for orbital group 1<br> Even tempered Ar P diffuse selected for group 1 nprim= 1 centre= 0.044 ratio= 2.497 dratio= 1.000<br> Library entry AR D def2-QZVP selected for orbital group 1<br> Even tempered Ar D diffuse selected for group 1 nprim= 1 centre= 0.123 ratio= 2.407 dratio= 1.000<br> Library entry AR F def2-QZVP selected for orbital group 1<br> Even tempered Ar F diffuse selected for group 1 nprim= 1 centre= 0.223 ratio= 2.440 dratio= 1.000<br> <span style="text-decoration: underline;">Library entry AR G def2-QZVP </span> selected for orbital group 1<br> Even tempered Ar G diffuse selected for group 1 nprim= 1 centre= 0.403 ratio= 2.500 dratio= 1.000<br><br> Library entry CS S def2-QZVP selected for orbital group 2<br> Even tempered Cs S diffuse selected for group 2 nprim= 1 centre= 0.008 ratio= 1.465 dratio= 1.000<br> Library entry CS P def2-QZVP selected for orbital group 2<br> Even tempered Cs P diffuse selected for group 2 nprim= 1 centre= 0.004 ratio= 2.468 dratio= 1.000<br> Library entry CS D def2-QZVP selected for orbital group 2<br> Even tempered Cs D diffuse selected for group 2 nprim= 1 centre= 0.004 ratio= 2.911 dratio= 1.000<br> <span style="text-decoration: underline;">Library entry CS F def2-QZVP</span> selected for orbital group 2<br> Even tempered Cs F diffuse selected for group 2 nprim= 1 centre= 0.235 ratio= 2.500 dratio= 1.000<br><br>For Rb (def2-qzvp with ecp28mdf)<br><br> Library entry Rb ECP ECP28MDF selected for group 2<br> Library entry AR S def2-QZVP selected for orbital group 1<br> Even tempered Ar S diffuse selected for group 1 nprim= 1 centre= 0.068 ratio= 2.441 dratio= 1.000<br> Library entry AR P def2-QZVP selected for orbital group 1<br> Even tempered Ar P diffuse selected for group 1 nprim= 1 centre= 0.044 ratio= 2.497 dratio= 1.000<br> Library entry AR D def2-QZVP selected for orbital group 1<br> Even tempered Ar D diffuse selected for group 1 nprim= 1 centre= 0.123 ratio= 2.407 dratio= 1.000<br> Library entry AR F def2-QZVP selected for orbital group 1<br> Even tempered Ar F diffuse selected for group 1 nprim= 1 centre= 0.223 ratio= 2.440 dratio= 1.000<br> <span style="text-decoration: underline;">Library entry AR G def2-QZVP </span> selected for orbital group 1<br> Even tempered Ar G diffuse selected for group 1 nprim= 1 centre= 0.403 ratio= 2.500 dratio= 1.000<br><br> Library entry RB S def2-QZVP selected for orbital group 2<br> Even tempered Rb S diffuse selected for group 2 nprim= 1 centre= 0.006 ratio= 2.064 dratio= 1.000<br> Library entry RB P def2-QZVP selected for orbital group 2<br> Even tempered Rb P diffuse selected for group 2 nprim= 1 centre= 0.005 ratio= 2.591 dratio= 1.000<br> Library entry RB D def2-QZVP selected for orbital group 2<br> Even tempered Rb D diffuse selected for group 2 nprim= 1 centre= 0.003 ratio= 2.877 dratio= 1.000<br> <span style="text-decoration: underline;">Library entry RB F def2-QZVP</span> selected for orbital group 2<br> Even tempered Rb F diffuse selected for group 2 nprim= 1 centre= 0.341 ratio= 2.500 dratio= 1.000<br><br>So, def2-aqzvp basis set can change its cardinal number n, but it is still called aqzvp!<br>Does it mean, that we should use different n (i.e. cardinal numbers or lmax of a particular basis set) in the extrapolation formulae for the same basis set, if lmax changes? <br><br>So, it is impossible to extrapolate the energy of the system, which contains atoms with different lmax (when we use def2-anzvp<br>basis sets), because in such a case n is not determined (something like (n1+n2)/2 - which is not even an integer). Am I right?<br><br>I am also interested in scientific papers, in which extrapolation to the complete basis set limit of def2-asvp/atzvp/aqzvp basis sets is carried out (if extrapolation is allowed for def2-anzvp basis sets).<br><br>Alexander Medvedev, <br>student of the 5th course of <div style="text-align: left;">Lomonosov Moscow State University<br>Department of Chemistry</div><div style="text-align: left;">Chair of Laser Chemistry</div><br></BODY></HTML>