Photodissociation Dynamics of CO-Forming Channels on the Ground-State Surface of Methyl Formate at 248 nm: Direct Dynamics Study and Assessment of Generalized Multicenter Impulsive Models

2021 ◽  
Vol 125 (5) ◽  
pp. 1198-1220
Author(s):  
Federico Palazzetti ◽  
Po-Yu Tsai
Keyword(s):  
Ground State ◽  
Methyl Formate ◽  
Direct Dynamics

Identification of a vibrationally excited level in methyl formate through microwave and far-infrared spectroscopy

2020 ◽  
Vol 98 (6) ◽  
pp. 551-554
Author(s):  
Kaori Kobayashi ◽  
Yusuke Sakai ◽  
Masaharu Fujitake ◽  
Dennis W. Tokaryk ◽  
Brant E. Billinghurst ◽  
...  
Keyword(s):  
Excited States ◽  
Ground State ◽  
Methyl Formate ◽  
Excited Level ◽  
Far Infrared ◽  
Infrared Region ◽  
Far Infrared Spectroscopy ◽  
Interstellar Molecule ◽  
Vibrationally Excited ◽  
Rotational Transitions

Methyl formate (HCOOCH3) is an important interstellar molecule. More than 1000 rotational transitions including those from the ground state, torsionally excited states, and of its isotopologues have been observed towards several astrophysical sources. The laboratory spectra of methyl formate in the microwave spectral region contain many unassigned transitions and many of them are likely to be due to rotational transitions in the low-lying excited states. We report the laboratory identification of new rotational transitions in the COC deformation (ν12) excited state. The identification was made possible by combining the microwave data with rotation–vibration spectra taken in the far-infrared region at the Canadian Light Source synchrotron.

Ab initio electronic structure and direct dynamics simulations of CH3OCl

2009 ◽  
Vol 87 (7) ◽  
pp. 1022-1029
Author(s):  
Stephanie Y. Y. Wong ◽  
Pierre-Nicholas Roy ◽  
Alex Brown
Keyword(s):  
Electronic Structure ◽  
Excited State ◽  
Ab Initio ◽  
Ground State ◽  
Basis Set ◽  
Ab Initio Molecular Dynamics ◽  
Basis Sets ◽  
Excitation Energies ◽  
Direct Dynamics ◽  
Ab Initio Electronic Structure

The ground (X1A′) and two lowest lying excited singlet states (11A″ and 21A′) of methyl hypochlorite have been examined using ab initio electronic structure techniques to validate computationally efficient methods, upon which direct dynamics can be based, versus high-level ones, for which direct dynamics would be intractable. Ground-state equilibrium geometries and vibrational frequencies determined using density functional theory (DFT) with the 6-31G(d) basis set are tested against coupled-cluster theory (CCSD(T)) results from the literature. Vertical excitation energies and transition dipole moments calculated at the complete active space self-consistent field CASSCF/6-31+G(d) level of theory are benchmarked against multireference configuration interaction (MRCI) results with the aug-cc-pVXZ (X = D, T, Q) family of basis sets. The excited-state gradients that will govern the classical dynamics are compared for CASSCF/6-31+G(d) versus MRCI/aug-cc-pVXZ (X = D, T). To carry out the ab initio molecular dynamics (AIMD), existing electronic structure codes have been interfaced with the molecular modelling toolkit (MMTK), an open-source program library for molecular simulation applications. We use two examples to demonstrate the use of direct dynamics in MMTK: a canonical ground-state trajectory to sample positions and momenta, and an excited-state microcanonical trajectory based on CASSCF. The work presented here forms the basis for future study of the photodissociation of CH3OCl. As well, the implementation of AIMD within MMTK provides a useful tool for examining a variety of other research problems.

scholarly journals The Millimeter‐ and Submillimeter‐Wave Spectrum of13C1‐Methyl Formate (H13COOCH3) in the Ground State

2008 ◽  
Vol 175 (1) ◽  
pp. 138-146 ◽  
Author(s):  
Atsuko Maeda ◽  
Ivan R. Medvedev ◽  
Frank C. De Lucia ◽  
Eric Herbst ◽  
Peter Groner
Keyword(s):  
Ground State ◽  
Methyl Formate ◽  
Wave Spectrum ◽  
Submillimeter Wave

Renilla Bioluminescence: A Morphologic Approach to the Location of Photocytes

1974 ◽  
Vol 32 ◽  
pp. 208-209
Author(s):  
Ben O. Spurlock ◽  
Milton J. Cormier
Keyword(s):  
Excited State ◽  
Ground State ◽  
Molecular Basis ◽  
Light Emission ◽  
Chemical Basis ◽  
Electronic Excited State ◽  
Colonial Form ◽  
The Common ◽  
Eighteenth And Nineteenth Centuries ◽  
Catalyzed Oxidation

The phenomenon of bioluminescence has fascinated layman and scientist alike for many centuries. During the eighteenth and nineteenth centuries a number of observations were reported on the physiology of bioluminescence in Renilla, the common sea pansy. More recently biochemists have directed their attention to the molecular basis of luminosity in this colonial form. These studies have centered primarily on defining the chemical basis for bioluminescence and its control. It is now established that bioluminescence in Renilla arises due to the luciferase-catalyzed oxidation of luciferin. This results in the creation of a product (oxyluciferin) in an electronic excited state. The transition of oxyluciferin from its excited state to the ground state leads to light emission.

Explicitly correlated Gaussian functions in variational calculations: the ground state of helium dimer

1997 ◽  
Vol 91 (5) ◽  
pp. 909-915 ◽  
Author(s):  
JACEK KOMASA ◽  
JACEK RYCHLEWSKI
Keyword(s):  
Ground State ◽  
Gaussian Functions ◽  
Variational Calculations ◽  
Explicitly Correlated

Progress on high precision calculations for the ground state of atomic lithium

1997 ◽  
Vol 400 (1-2) ◽  
pp. 7-56 ◽  
Author(s):  
F King
Keyword(s):  
High Precision ◽  
Ground State

Theoretical study of the homologous reactions of ground-state oxygen atoms with Br2 and BrCI molecules

1995 ◽  
Vol 92 ◽  
pp. 1214-1232 ◽  
Author(s):  
E Drougas ◽  
AM Kosmas
Keyword(s):  
Ground State ◽  
Theoretical Study ◽  
Oxygen Atoms

The ground state energy of the ±J spin glass from the genetic algorithm

1994 ◽  
Vol 4 (9) ◽  
pp. 1281-1285 ◽  
Author(s):  
P. Sutton ◽  
D. L. Hunter ◽  
N. Jan
Keyword(s):  
Genetic Algorithm ◽  
Spin Glass ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy
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