The potential energy surfaces of the ground and excited states of carbon dioxide molecule

Abstract

Potential energy surfaces (PESs) of the 1 A l ( ), 1 B 2 and 3 B 2 electronic states of CO 2 have been computed as a function of the two bond distances and the bond angle. The calculations were based on the complete active space self consistent field (CASSCF) and multiconfigurational second order perturbation theory (CASPT2) electronic structure models. From our calculations no crossing point between 1 B 2 and 3 B 2 states was found, but there is a crossing point located between 1 B 2 and 3 A 2 state on the PESs. The energy of the crossing point is lie 0.23 eV above the CO + O ( 3 P), which is in agreement with the value of 0.27 eV on the experiment. This implies that the mechanism of the recombination of an oxygen atom with a carbon monoxide molecule: CO(X 1 Σ + , ν) + O( 3 P) 3 C 1 C CO(X 1 Σ + , ν = 0) + O( 1 D) may occur through the 3 A 2 state crossing the 1 B 2 state. The equilibrium geometries and adiabatic excitation energies of 1,3 B 2 , 1,3 A 2 states of CO 2 were reported and discussed in this paper, too.

Temperature dependence of the photodissociation of CO2 from high vibrational levels: 205-230 nm imaging studies of CO(X1Σ+) and O(3P, 1D) products

“…86 Several recent theoretical papers have examined the recombination reaction, identifying spinorbit couplings and conical intersections. 11,[44][45][46][47][48] Even though these calculations do not include the highly excited CO 2 vibrational levels that are necessary to describe fully our results, they indicate that more than one reaction mechanism must be involved. The calculations show the participation of a direct (or non-statistical) mechanism, which is too fast to allow for randomization of energy, and an indirect (or statisticallike) route, in which at least some energy randomization takes place.…”

“…Several theoretical studies have focused on the excited electronic states of CO 2 at 4-9 eV, [9][10][11]44,47,48 and on the interactions among states that are involved in the dissociation. 9,44 Schmidt et al computed 1D potential energy curves for the electronic states of CO 2 as a function of OC-O internuclear distance (C s ) and OCO bond angle (C 2v ).…”

“…Several theoretical studies address the recombination of O( 3 P) and CO to the ground singlet state of CO 2 , which must involve spin-orbit couplings. 42,[44][45][46][47][48] The interest in the behavior of CO 2 in high temperature environments has also prompted extensive studies of its rovibrational spectroscopy. The well-known Fermi resonance between the CO 2 symmetric stretch and two quanta of bend leads to a complicated vibrational band structure, 49 with vibrational transitions organized in polyads.…”

Towards recognizing the mechanisms of effects evoked in living organisms by static magnetic field. Numerically simulated effects of the static magnetic field upon simple inorganic molecules.

“…Carbon dioxide represents a π-electron system. Hence, because of the mobility of the π-electrons 44,45 unexpected behaviour of the molecule placed in SMF might be anticipated. Thus, the length of both C=O bonds changed with increase in T but at 0.1 and 100T both bonds had slightly different length, perhaps mainly because of limited precision of calculations.…”