The ab initio calculation of molecular geometrical properties in the HellmannFeynman approximation is discussed in which the atomic orbitals are fixed at the positions of the nuclei at the reference geometry, thereby avoiding the calculation of derivatives of the molecular integrals with respect to the...
Molecular mechanics calculationsusing MMX-93 field were performed for four conformations of 4-methyl-6-phenyl-2,3,4,6-tetrahydrobenzo[f][1,5,2]dioxazocine6to predict its conformational behavior in solid state and solution<1995NJC1099>. Conformations of6are determined by vicinal lone pair electros...
The objective of this computational note is to report the results of the calculation of the molecular structure and prop-erties of 3-(2-pyrrolyl)-3,4-diphenyl 1,2,5-thiadiazoline 1,1-diox-ide and 2-benzoyl-3,4-diphenyl 1,2,5-thiadiazoline 1,1-dioxide [1] using a recently ...
molecular fine structureorganic compoundsorganic molecule configurationsparamagnetic resonance of free radicals/ geometryspatially hinderedquinonesphenolsESR spectraradical pairsGeometry of the binary complex of 3,6-di-t-butyl-o-quinone and 2,4,6-tri-t-butyl phenol is investigated. Photolysis of this ...
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The crystal structure of 1 has been determined by X-ray single crystal diffraction. The complex crystallizes in orthorhombic system with space group Pnma. In 1, Ni(II) ion is five coordinated with square-pyramidal geometry defined by the four C atoms from the four symmetry related cyano ...
Hydrogen causes the lattice distortion,the volume and volume expansion rate of α-Ti-H crystals increase with the addition of H atom; The total energies and impurity formation energies decrease with the increasing of H atom. Lattice distortion provides energy for the formation of Ti-H compounds;...
The new method has been applied to the calculation of crambin using PM3, in which the geometry was defined using Cartesian coordinates for the molecular backbone and internal coordinates for the side chains. 展开 关键词: BFGS Geometry optimization Semiempirical DOI: 10.1016/S0166-1280(97)00050-...
molecular momentsThe electronic structure of the isolated [F(HF) 2] complex is calculated at the MP2/6-311++G(3df,3pd) level with the correction for the basis set superposition error taken into account. The equilibrium geometry of the complex is determined. Based on the four-dimensional (...
A DFT/B3LYP method has been used for analysis of the vibrational spectra and geometric structure of pyrrole and other heterocyclic compounds in the anharmonic approximation<2007MI169>. The B3LYP/6-31+G(d) molecular geometry-optimized structures of 17 five-membered heterocycles were employed together...