From chemistry-request {*at*} server.ccl.net Tue May 21 07:15:47 2002 Received: from uscmail.usc.es ([193.144.75.8]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id g4LBFk119047 for ; Tue, 21 May 2002 07:15:47 -0400 Received: from qfcronos (qfcronos.usc.es [193.144.74.154]) by uscmail.usc.es (8.9.1/8.9.1) with SMTP id NAA20536 for ; Tue, 21 May 2002 13:15:31 +0200 (MET DST) Message-ID: <003601c200b8$f5695a60$9a4a90c1 -8 at 8- usc.es> From: =?iso-8859-1?Q?Jes=FAs_Rodr=EDguez_Otero?= To: Subject: question about the CHOOSE keyword in NBO Date: Tue, 21 May 2002 13:16:29 +0200 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0033_01C200C9.B828BFE0" 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 This is a multi-part message in MIME format. ------=_NextPart_000_0033_01C200C9.B828BFE0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi I have a doubt about the operation of analysis NBO searching the best = Lewis structure. The description of Lewis of a certain molecule gives me a little strange = result. Then I repeat the calculation on the same molecule with the = option CHOOSE (DIRECTED NBO SEARCH) choosing a more "normal" structure = of Lewis and in this second calculation I obtain a smaller Dev and = smaller Total non-Lewis.=20 This is normal? Because I thought that in the process of optimization = NBO the structure with a smaller amount of non-Lewis and a smaller Dev = would have to be obtained. Thanks ******************************************* Without CHOOSE (free NBO search): ******************************************* NATURAL BOND ORBITAL ANALYSIS: Cycle Thresh. Lewis Non-Lewis CR BD 3C LP (L) (NL) Dev =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=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 1(1) 1.90 33.82805 2.17195 5 11 0 2 2 3 0.59 2(2) 1.90 33.82805 2.17195 5 11 0 2 2 3 0.59 3(1) 1.80 34.34760 1.65240 5 12 0 1 2 3 0.59 4(2) 1.80 33.42460 2.57540 5 13 0 0 4 5 0.59 . . 38(9) 1.50 34.21710 1.78290 5 11 0 2 1 3 0.37 39(1) 1.70 34.54664 1.45336 5 12 0 1 1 3 0.37 -------------------------------------------------------------------------= ---- Total non-Lewis 1.45336 ( 4.037% of 36) -------------------------------------------------------- ******************* With CHOOSE: ******************* NATURAL BOND ORBITAL ANALYSIS: Cycle Thresh. Lewis Non-Lewis CR BD 3C LP (L) (NL) Dev =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=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 1(1) 1.90 34.72964 1.27036 5 12 0 1 3 3 0.34 -------------------------------------------------------------------------= ---- Total non-Lewis 1.27036 ( 3.529% of 36) ------=_NextPart_000_0033_01C200C9.B828BFE0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

I have a doubt about the operation of analysis NBO searching the best = Lewis=20 structure.

The description of Lewis of a certain molecule gives me a little = strange=20 result. Then I repeat the calculation on the same molecule with the = option=20 CHOOSE (DIRECTED NBO SEARCH) choosing a more "normal" structure of Lewis = and in=20 this second calculation I obtain a smaller Dev and smaller Total = non-Lewis.

This is normal? Because I thought that in the process of optimization = NBO the=20 structure with a smaller amount of non-Lewis and a smaller Dev would = have to be=20 obtained.

Thanks

*******************************************

Without CHOOSE (free NBO search):

*******************************************

NATURAL BOND ORBITAL ANALYSIS:

Cycle Thresh. Lewis Non-Lewis CR BD 3C LP (L) (NL) Dev

=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=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

1(1) 1.90 33.82805 2.17195 5 11 0 2 2 3 0.59

2(2) 1.90 33.82805 2.17195 5 11 0 2 2 3 0.59

3(1) 1.80 34.34760 1.65240 5 12 0 1 2 3 0.59

4(2) 1.80 33.42460 2.57540 5 13 0 0 4 5 0.59

38(9) 1.50 34.21710 1.78290 5 11 0 2 1 3 0.37

39(1) 1.70 34.54664 1.45336 5 12 0 1 1 3 = 0.37

--------------------------------------------------------------------= ---------

Total non-Lewis 1.45336 ( 4.037% of 36)

--------------------------------------------------------

*******************

With CHOOSE:

*******************

NATURAL BOND ORBITAL ANALYSIS:

Cycle Thresh. Lewis Non-Lewis CR BD 3C LP (L) (NL) Dev

1(1) 1.90 34.72964 1.27036 5 12 0 1 3 3 0.34

--------------------------------------------------------------------= ---------

Total non-Lewis 1.27036 ( 3.529% of=20 36)

------=_NextPart_000_0033_01C200C9.B828BFE0--