From chemistry-request@server.ccl.net Wed Apr 24 06:45:29 2002 Received: from relay.unizar.es ([155.210.3.20]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id g3OAjSA22530 for ; Wed, 24 Apr 2002 06:45:28 -0400 Received: from posta.unizar.es (root@posta.unizar.es [155.210.11.16]) by relay.unizar.es (8.11.1/8.11.1) with ESMTP id g3OAjFp22841 for ; Wed, 24 Apr 2002 12:45:15 +0200 (MET DST) Received: from QOTTFP4 ([155.210.90.178]) by posta.unizar.es (8.11.1/8.11.1) with SMTP id g3OAgE829684 for ; Wed, 24 Apr 2002 12:42:14 +0200 (MET DST) Message-ID: <001201c1eb7d$1b13db10$b25ad29b@QOTTFP4> From: =?iso-8859-1?Q?Jes=FAs_Orduna?= To: "CCL" Subject: Two photon absorption cross section units Date: Wed, 24 Apr 2002 12:45:09 +0200 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000F_01C1EB8D.DE551AC0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Virus-Scanned: TAMIZ + Sophos en unizar.es This is a multi-part message in MIME format. ------=_NextPart_000_000F_01C1EB8D.DE551AC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable dear CCLers, I am becoming interested in Two Photon Absortion (TPA) processes and the = use of quantum chemical calculations to predict TPA cross sections. > From a three level aproach, the TPA cross section is expresed as: (mu(0,1))^2 (mu(1,2))^2/(delta E)^2 So it should have the dimensions of "dipole moment^4/Energy^2" but the TPA cross section is usually expresed in "cm^4 s/molecule" units = which at least at first sight have a completely different dimension. Could somebody clarify the relationship between these ways to express = the TPA cross sections? How can I convert calculated croos sections in atomic units to cm^4 = s/molecule? Thanks =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D Jes=FAs Orduna Instituto de Ciencia de Materiales de Aragon Unidad de Nuevos Materiales Org=E1nicos Facultad de Ciencias CSIC-Universidad de Zaragoza E-50009 Zaragoza (Spain) Phone/FAX: +34 976 761194 e-mail: jorduna@posta.unizar.es =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D ------=_NextPart_000_000F_01C1EB8D.DE551AC0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

dear CCLers,

I am becoming interested in Two Photon = Absortion=20 (TPA) processes and the use of quantum chemical calculations to predict = TPA=20 cross sections.

From a three level aproach, the TPA = cross section=20 is expresed as:

(mu(0,1))^2 (mu(1,2))^2/(delta=20 E)^2

So it should have the dimensions = of "dipole=20 moment^4/Energy^2"

but the TPA cross section is usually = expresed in=20 "cm^4 s/molecule" units which at least at first sight have a completely=20 different dimension.

Could somebody clarify the relationship = between=20 these ways to express the TPA cross sections?

How can I convert calculated croos = sections in=20 atomic units to cm^4 s/molecule?

Thanks

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
Jes= =FAs Orduna
Instituto=20 de Ciencia de Materiales de Aragon
Unidad de Nuevos Materiales=20 Org=E1nicos
Facultad de Ciencias
CSIC-Universidad de = Zaragoza
E-50009=20 Zaragoza (Spain)
Phone/FAX: +34 976 761194
e-mail: jorduna@posta.unizar.es
=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

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