MR-CISD and MR-AQCC Calculation of Excited States of Malonaldehyde: Geometry Optimizations Using Analytical Energy Gradient Methods and a Systematic Investigation of Reference Configuration Sets

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Title:MR-CISD and MR-AQCC Calculation of Excited States of Malonaldehyde: Geometry Optimizations Using Analytical Energy Gradient Methods and a Systematic Investigation of Reference Configuration Sets
Creators:
Monte, Silmar A. do
Dallos, Michal
Müller, Thomas
Lischka, Hans
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 68, 3, pp. 447-462
Uncontrolled Keywords:<i>Ab initio</i> calculations, Malonaldehyde, Proton transfer, Hydrogen bond, Multireference configuration interaction, Excited states

Abstract

Extended MR-CISD and MR-AQCC calculations have been performed on the ground state and the first two excited states of malonaldehyde. Full geometry optimizations have been carried for <i>C</i><sub>s</sub> and <i>C</i><sub>2v</sub> structures both at MR-CISD and MR-AQCC levels. Vertical and minimum-to-minimum excitation energies and oscillator strengths have been computed. Systematic studies have been undertaken concerning several types of reference spaces. Agreement with the experimental 0-0 transition energy to the S<sub>1</sub> state (expt. 3.50 eV, calc. 3.56 eV) and for the vertical excitation to S<sub>2</sub> (expt. band maximum 4.71 eV, best estimate 4.86 eV) is very good. In agreement with the CASSCF/CASPT2 results by Sobolewski and Domcke (<i>J. Phys. Chem. A</i> <strong>1999</strong>, <i>103</i>, 4494), we find that the hydrogen bond in malonaldehyde is weakened by excitation to the S<sub>1</sub> state. The barrier for proton transfer in the S<sub>1</sub> state is increased in comparison with the ground state. <p>

Title:MR-CISD and MR-AQCC Calculation of Excited States of Malonaldehyde: Geometry Optimizations Using Analytical Energy Gradient Methods and a Systematic Investigation of Reference Configuration Sets
Creators:
Monte, Silmar A. do
Dallos, Michal
Müller, Thomas
Lischka, Hans
Uncontrolled Keywords:<i>Ab initio</i> calculations, Malonaldehyde, Proton transfer, Hydrogen bond, Multireference configuration interaction, Excited states
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:68
Number:3
Page Range:pp. 447-462
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20030447UNSPECIFIED
ID Code:2068
Item Type:Article
Deposited On:06 Feb 2009 17:15
Last Modified:06 Feb 2009 16:15

Citation

Monte, Silmar A. do; Dallos, Michal; Müller, Thomas; Lischka, Hans (2003) MR-CISD and MR-AQCC Calculation of Excited States of Malonaldehyde: Geometry Optimizations Using Analytical Energy Gradient Methods and a Systematic Investigation of Reference Configuration Sets. Collection of Czechoslovak Chemical Communications, 68 (3). pp. 447-462. ISSN 0010-0765

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