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Dear Martin,
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<div class="">within the usual Born-Oppenheimer approximation, the PES is the solution to the electronic Schrödinger equation which is then used as an effective potential for nuclear motion to solve the nuclear motion S.E, i.e., vibrational eigenvalues. If
the BO approximation is valid, the usual PES has a very usual interpretation. Somehow defining a whole PES with vibrational motion included makes no sense to me - how do you define vibrational zero-point corrections when the 1st derivatives are non-zero everywhere
(except the minimum) ? The harmonic approximation will also presumably be very bad away from the minimum. Certain approximations can be made along reaction coordinates, but in general I don’t see either the benefit or theoretical rationale for what you suggest.</div>
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<div class="">just my 2 cents,</div>
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<div class="">-Kirk</div>
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<div class="">On Dec 30, 2014, at 8:33 AM, Martin Spenke <<a href="mailto:martinspenke@yahoo.de" class="">martinspenke@yahoo.de</a>> wrote:</div>
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<div id="yui_3_16_0_1_1419955666725_3362" dir="ltr" class=""><span class="">Dear Peter, </span></div>
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<div id="yui_3_16_0_1_1419955666725_3362" dir="ltr" class=""><span id="yui_3_16_0_1_1419955666725_3747" class="">The well-defined problem is that the transition structure </span></div>
<div id="yui_3_16_0_1_1419955666725_3362" dir="ltr" class=""><span id="yui_3_16_0_1_1419955666725_6518" class="">on an enthalpy surface </span>lacks vibrational energy. </div>
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<div id="yui_3_16_0_1_1419955666725_3362" dir="ltr" class="" style="">The usual calculated PES is thus physically an unrealistic surface, therefore </div>
<div id="yui_3_16_0_1_1419955666725_3362" dir="ltr" class="" style="">the whole PES (namely each point) should be vibrationally</div>
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<div id="yui_3_16_0_1_1419955666725_3362" dir="ltr" class="">corrected, not only for minimum points but for all.</div>
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<div id="yui_3_16_0_1_1419955666725_3362" dir="ltr" class="">I guess i have to calculate for every single point on a full optimized PES,</div>
<div id="yui_3_16_0_1_1419955666725_3362" dir="ltr" class="">ZPEs and add it to electronic energies afterwards to accomplish the physically realistic one.</div>
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<div id="yui_3_16_0_1_1419955666725_3362" dir="ltr" class="">Bests</div>
<div id="yui_3_16_0_1_1419955666725_3362" dir="ltr" class="">Martin </div>
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<div dir="ltr" class=""><font size="2" face="Arial" class="">Peter Reinhardt <<a href="mailto:Peter.Reinhardt@upmc.fr" class="">Peter.Reinhardt@upmc.fr</a>> schrieb am 10:31 Dienstag, 30.Dezember 2014:<br class="">
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<div class="y_msg_container">Dear Martin,<br clear="none" class="">
I'm not sure whether this is a well-defined problem as the zero-point<br clear="none" class="">
energy applies to the minimum around which the PES is expanded in a<br clear="none" class="">
quadratic form. ZPE concerns the nuclear motion, not the electronic problem.<br clear="none" class="">
<br clear="none" class="">
Yours,<br clear="none" class="">
Peter<br clear="none" class="">
<div class="yqt6121155964" id="yqtfd10606"><br clear="none" class="">
Martin Spenke wrote:<br clear="none" class="">
> Dear all, <br clear="none" class="">
> Is it with molpro possible to calculate PES with the inclusion of zero<br clear="none" class="">
> point motion corrections to the energy points of the surface at mrci<br clear="none" class="">
> level?If yes, what is the keyword for this ?<br clear="none" class="">
> BestsMartin_______________________________________________</div>
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> Molpro-user mailing list<br clear="none" class="">
> <a shape="rect" ymailto="mailto:Molpro-user@molpro.net" href="mailto:Molpro-user@molpro.net" class="">
Molpro-user@molpro.net</a><br clear="none" class="">
> <a shape="rect" href="http://www.molpro.net/mailman/listinfo/molpro-user" target="_blank" class="">
http://www.molpro.net/mailman/listinfo/molpro-user</a><br clear="none" class="">
<br clear="none" class="">
<br clear="none" class="">
-- <br clear="none" class="">
v v v v v v v v v v v v v v v v v v v v v<br clear="none" class="">
> Dr. Peter Reinhardt | Maître de Conférences <<br clear="none" class="">
> Lab. Chimie Théorique | (HDR) <<br clear="none" class="">
> Université P et M Curie | tour 12-13, 4e étage <<br clear="none" class="">
> 4 place Jussieu, case 137 | Tél.: +33(0)1 44 27 9657 <<br clear="none" class="">
> F -- 75252 Paris, France | Fax.: 4117 <<br clear="none" class="">
> email: <a shape="rect" ymailto="mailto:Peter.Reinhardt@upmc.fr" href="mailto:Peter.Reinhardt@upmc.fr" class="">
Peter.Reinhardt@upmc.fr</a> <<br clear="none" class="">
> Web: <a shape="rect" href="http://www.lct.jussieu.fr/pagesperso/reinh" target="_blank" class="">
http://www.lct.jussieu.fr/pagesperso/reinh </a>
<div class="yqt6121155964" id="yqtfd72140"> <<br clear="none" class="">
^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^<br clear="none" class="">
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