[FeFe]-hydrogenases are the best natural hydrogen-producing enzymes but their biotechnological exploitation is hampered by their extreme oxygen sensitivity. The free energy profile for the chemical attachment of O2 to the enzyme active site was investigated by using a range-separated density functional re-parametrized to reproduce high-level ab initio data. An activation free-energy barrier of ...

We present an atomistic potential for BiFeO(3) based on the principles of bond-valence (BV) and bond-valence vector (BVV) conservation. The validity of this model potential is tested for both canonical ensemble (NVT) and isobaric-isothermal ensemble (NPT) molecular dynamics (MD) simulations. The model reproduces the ferroelectric-to-paraelectric phase transition in both NVT and NPT MD simulati...

Generalized valence bond plus configuration interaction calculations have been carried out on the monopositive diatomic metal hydride ions of the second transition-metal series (YH+-CdH+, including SrH'). We analyze the trends in bond energies, equilibrium geometries, vibrational frequencies, and metal orbital hybridizations. The trends in these quantities can be understood in terms of (1) the ...

Theoretical methods are reported for ab initio calculations of the adiabatic (Born-Oppenheimer) electronic wave functions and potential energy surfaces of molecules and other atomic aggregates. An outer product of complete sets of atomic eigenstates familiar from perturbation-theoretical treatments of long-range interactions is employed as a representational basis without prior enforcement of a...

A unified interface that can seamlessly merge real/virtual spaces or local/remote spaces are presented as a bi-directional energy interface. An arbitrary system consisted of real/virtual objects has some energy connections between the objects of the system. These energy connections can be simply described by bond graphs. Using the mathematical modeling derived from the bond graphs of the system...

The UV-Vis absorption spectrum and LIF emission spectrum of I2 were found for the purpose of gaining information about the energy of the ground X( 1 Σg + ) and excited B( 3 Π0u + ) states. This information was compared to information obtained from the Gaussian program which uses quantum mechanical calculations and numerical approximations to predict electronic energy levels. The iodine molecule...

Collision-induced dissociation (CID) rates are measured for a suite of lanthanide (plus yttrium) monoxide ions stored in a quadrupole ion trap. Yttrium, neodymium, and gadolinium oxides, having the same nominal dissociation energy (D0 ≈ 735 kJ mol−1) but different masses, provide an empirical correction of −1.2 s−1 amu−1 for the measured CID rates. The CID rate correction enables the correlatio...

The aim of this research is studying the effects of Ge-doped on CO adsorption on the outer and inner surfaces of (6, 0) zigzag model of boron nitride nanotube (BNNTs) by using DFT theory. For this purpose, eight models of CO adsorption on the surfaces of BNNTs are considered. At first step, all structures were optimized at B3LYP and 6-31G (d) standard base set and then the electronic structure,...

Density functional theory methods(DFT) and natural bond orbital (NBO) analysis were used to investigate the effects of isomerism and side chain mutation at a microscopic level on the stability, binding energy and NMR/NQR tensors of structural isomers, L- methionylasparagine (Met-Asn) and L- asparagylmethionine (Asn-Met) in the gas phase. The results represented that the isomerism and side chain...

The test system for emulsion pump is facing serious challenges due to its huge energy consumption and waste nowadays. To settle this energy issue, a novel energy regenerative system (ERS) for emulsion pump tests is briefly introduced at first. Modeling such an ERS of multienergy domains needs a unified and systematic approach. Bond graph modeling is well suited for this task. The bond graph mod...