The equilibrium structure and potential energy surface of calcium monohydroxide in its ground doublet state, X2Σ+ CaOH, have been determined from large-scale ab initio calculations using the spin-restricted coupled-cluster method, RCCSD(T), with basis sets quadruple- quintuple-ζ quality. vibrational−rotational levels CaOH CaOD isotopomers were calculated variational method. spectroscopic constants are found to be remarkably good agreement experimental data.

Abstract AM1 and PM3 semiempirical calculations are reported for the solvent effects on tautomeric equilibria of 2‐pyridone/2‐hydroxypyridine 4‐pyridone/4‐hydroxypyridine in gas phase solution. The were investigated by self‐consistent reaction field (SCRF) theory implemented AMPAC MOPAC program two different ways: one which all relaxation is included quantum mechanics total energy must be corrected change energy, method A; a second directly includes this term, B. calculated (AM1, A)...

Solvent effects on the spectroscopic properties of lumichromes and lumiflavins are presented. Fluorescence yields for an order magnitude larger than those lumichromes, due to their lower nonradiative rate constants. absorption emission band positions explained basis hydrogen-bonding interactions. TD-DFT calculations predicted that lowest energy states n,π* in case but π,π* lumiflavins. The overall consistency singlet−singlet triplet−triplet transitions obtained various compounds studied,...

In this overview we discuss the vibrational spectrum of phosphaethyne, HCP, in its electronic ground state, as revealed by complementary experimental and theoretical examinations. The main focus is evolution specific spectral patterns from bottom potential well up to excitation energies approximately 25,000 cm(-1), where large-amplitude, isomerization-type motion H-CP CP-H prominent. Distinct structural dynamical changes, caused an abrupt transformation essentially HC bonding mainly PH...

The six-dimensional potential energy surface of hydrogen peroxide, H2O2, has been determined from large-scale ab initio calculations using the coupled-cluster method, CCSD(T), with basis set quadruple-ζ quality, cc-pVQZ. effects core-electron correlation on calculated structural parameters and torsional function have investigated. anharmonic quartic force field determined. vibrational−rotational levels molecule then variational method. molecular properties are found to be in good agreement...

An asymmetrically substituted mono-amino Zn(<sc>ii</sc>) phthalocyanine exhibits an unexpected tendency to form emissive H-type dimers and higher order aggregates.

The vibrational-rotational energy levels of the hydrogen peroxide isotopomers H2O2, D2O2, HOOD, and H218O2 have been predicted by variational method using a high-quality ab initio six-dimensional potential surface. calculated are found to be in good agreement with available experimental data. spectroscopic constants for various can useful future analysis rotational-torsional spectra determination equilibrium structure peroxide.

In the course of 266 nm nanosecond laser flash photolysis carbazole (CBL) in acetonitrile, we discovered a new transient absorption band centered at 360 that has been heretofore unreported despite numerous reports on similar topics. To put some limits possible transients responsible for this and thus to solve mechanism CBL photolysis, employed strategy selectively blocking active sites by various modifications structure. This was supported use solvent effect triplet quenching molecular...

We have made energy-momentum maps for the experimental end-over-end rotational energy and two-dimensional bending vibrational energy, both of which confirm dominating effects nontrivial quantum monodromy in cyanogen isothiocyanate. Accidental resonances spectra yield accurate intervals between states.

The accurate ground-state potential energy function of the beryllium dimer, Be(2), has been determined from large-scale ab initio calculations using single-reference coupled-cluster approach in conjunction with correlation-consistent core-valence basis sets up to septuple-zeta quality. Results obtained conventional and explicitly-correlated methods were compared. scalar relativistic adiabatic (the diagonal correction) effects also discussed. vibration-rotation levels Be(2) predicted found be...

Lumichrome photophysical properties at different pH were characterized by UV-vis spectroscopy and steady-state time-resolved fluorescence techniques, in four forms of protonation/deprotonation: neutral form, two monoanions, dianion. The excited-state lifetimes these lumichrome measured discussed. results compared to those obtained for similar alloxazine and/or isoalloxazine, also 1-methyl- 3-methyllumichrome 1,3-dimethyllumichrome. absorption, emission, synchronous spectra lumichrome,...

ABSTRACT New molecular line lists for lithium hydroxide (6Li16O1H and 7Li16O1H isotopologues) covering wavelengths λ &amp;gt; 1 $\mu$m (0–10 000 cm−1 range) are presented. Each list contains around 300 million transitions between rotation–vibration energy levels with total angular momentum up to J = 95, applicable temperatures T ≈ 3500 K. Line calculations were based on a previously published, high-level ab initio potential surface newly computed dipole moment of the ground $\tilde{X}\,...

Abstract The accurate ground‐state potential energy surface of hydrogen peroxide, H 2 O , has been determined from ab initio calculations using the coupled‐cluster approach in conjunction with correlation‐consistent basis sets up to septuple‐zeta quality. Results obtained conventional and explicitly correlated methods were compared. core–electron correlation, scalar relativistic, higher‐order valence–electron correlation effects taken into account. adiabatic also discussed....

A detailed analysis of the bound-state spectrum HOCl (hypoclorous acid) in ground electronic state is presented. Exact quantum mechanical calculations (filter diagonalization) are performed employing an ab initio potential energy surface, which has been constructed using multireference configuration-interaction method and a quintuple-zeta one-particle basis set. The wave functions all bound states up to HO+Cl dissociation threshold visually inspected order assign rigorous way elucidate how...

The equilibrium structure and potential energy surface of beryllium dihydride BeH(2) in its ground electronic state have been determined from highly accurate ab initio calculations. vibration-rotation levels three isotopomers BeH(2), BeD(2), BeHD were predicted using the variational method. calculated spectroscopic constants are remarkably good agreement with existing experimental data (sub-cm(-1) accuracy) should be useful a further analysis high-resolution spectra all isotopomers.

The hydrogen bond energies for 4H-1-benzopyrane-4-thione (BPT) in its ground and two lowest excited singlet electronic states have been determined using ab initio methods. It was shown that the BPT molecule can form, as an acceptor, four relatively strong bonds with water molecules, leading to a stable complex state S(0). involving sulfur atom from thiocarbonyl group were found be stronger than those oxygen benzopyran moiety. former predicted become significantly weaker upon excitation S(1)...