From chemistry-request -8 at 8- server.ccl.net Wed Aug  7 13:53:17 2002
Received: from sgofims02.ccs.ppg.com ([141.189.251.1])
	by server.ccl.net (8.11.6/8.11.0) with ESMTP id g77HrHl13208
	for <chemistry ":at:" ccl.net>; Wed, 7 Aug 2002 13:53:17 -0400
Received: by sgofims02.ccs.ppg.com with Internet Mail Service (5.5.2653.19)
	id <P7R1JPCB>; Wed, 7 Aug 2002 13:53:13 -0400
Message-ID: <2195C52A2E0BD41190CB0090273F72E504390659 ":at:" sgofusr09.ccs.ppg.com>
From: "Deng, Jun" <jdeng:~at~:ppg.com>
To: chemistry(+ at +)ccl.net
Subject: TDDFT question
Date: Wed, 7 Aug 2002 13:53:11 -0400 
MIME-Version: 1.0
X-Mailer: Internet Mail Service (5.5.2653.19)
Content-Type: text/plain;
	charset="iso-8859-1"

Hi,

Does anyone has experience in TDDFT calculation on a charged molecule?  
I found that for neutral compounds, TDDFT generally gives smaller excitation energy than experiment for neutral compounds.  However, for charged molecules, it gives much, much higher energy.  Why?  Any suggestion?

Thank you all in advance!

***********************************************************************
Jun Deng                                          440 College Park Drive
Senior Research Chemist                   Monroeville, PA 15146
Applied Scientific Computing                 Tel:  (724) 325-5243
Monroeville Technical Center                 Fax: (724) 325-5225
PPG Industries, Inc.                        E-mail: jdeng;at;ppg.com
***********************************************************************